Andrea Moreira-Gonzalez

Clinical outcome in cranioplasty: critical review in long-term follow-up.

Various materials have been proposed for cranial reconstruction. Bone autograft and alloplasts such as polymethylmethacrylate (PMMA) and hydroxyapatite (HA) cement are most commonly used at the present time. Patients submitted for cranioplasty were evaluated. The prognostic factors influencing the results and the outcome were analyzed. Three hundred twelve patients who had 449 procedures performed by a single surgeon to reconstruct a calvarial deformity between 1981 and 2001 were studied. Post-tumor resection deformity was the main reason for cranioplasty (32.4%). Bone graft was the material of choice (69.5%). The main surgical site was the frontal bone (53.2%). Complications were observed in 23.6% of cases and were responsible for the least satisfactory results (P > 0.001), with infection and material exposure being the most critical complications. The eventual outcome was considered good in 91.8% of cases. The use of HA cement was associated with the worst results (P > 0.001). Bone grafts showed a high grade of partial resorption and required further surgery for correction. Multiple surgical procedures were correlated with a high rate of complications and an unsatisfactory outcome. Bone graft and PMMA are still the best materials in calvarial reconstruction. Even though HA cement is an osteoconductive material, it seems to induce what appears to be an immunoguided delayed inflammatory reaction that leads to thinning of the skin and exposure of the material, making secondary repair difficult. Before deciding which reconstructive option to use, a careful evaluation of the patient in terms of diagnosis, number of previous surgeries, and surgical site should be undertaken. If this is adopted, good results and a satisfactory outcome can be achieved on long-term follow-up.

Use of calcium-based bone cements in the repair of large, full-thickness cranial defects: a caution.

Background: Calcium-based bone cements have increased in popularity for the correction of craniofacial contour defects. The authors’ experience with them in more than 120 patients has resulted in the establishment of strict criteria for their use. Although the authors’ overall complication rate with these cements has been low, certain patient groups have an unacceptably high complication rate. The authors describe their experience with the repair of large, full-thickness cranial defects using calcium-based bone cements. Methods: The study group comprised 16 patients who underwent correction of large, full-thickness (>25 cm2) skull defects. The surgical technique included reconstruction of the floor of the defect with rigid fixation to the surrounding native bone, interposition of the cement to ideal contour, and closure of the defect. Results: The mean patient age was 35 years (range, 1 to 69 years). The mean defect area was 66.4 cm2 (range, 30 to 150 cm2). Cases were equally divided between BoneSource and Norian CRS. The mean amount of bone cement used was 80 g. Follow-up varied between 1 and 6 years (mean, 3 years). Major complications occurred in eight of 16 patients, with one occurring as late as 6 years postoperatively. Complications occurred throughout the course of review, indicating that they were not caused by a learning curve. Conclusion: Because of the unacceptably high complication rate with the use of calcium-based bone cements in large skull defects, the authors believe that their use is contraindicated and have returned to using autogenous split skull cranial bone reconstruction for these patients.

Calvarial thickness and its relation to cranial bone harvest.

Background: The purpose of this study was to define the variability in skull thickness from location to location and from individual to individual in a large number of human skulls. Method: Skull thickness was measured in multiple areas of the calvaria in 281 dry skulls from the Hamman-Todd osteological collection (Cleveland Museum of Natural History, Cleveland, Ohio). A total of 40 points were determined over the frontal, occipital, and parietal bones, with a higher number of points concentrated on the latter. Repeated measures analysis of variance models were used to assess the effects of covariates (individual variables) on skull thickness and location. Result: A statistically significant pattern of increased thickness toward the posterior parietal bones was seen in all subgroups. The mean thickness of the skull across all locations was 6.32 mm (SEM, 0.07 mm) and ranged from 5.3 mm (SEM, 0.09 mm) to 7.5 mm (SEM, 0.09 mm). Age was not found to be a significant predictor of mean skull thickness. Differences between male and female skulls were greater toward the rear of the parietal bones. Conclusion: The thickest area of the skull is the parasagittal posterior parietal area in male skulls and the posterior parietal area midway between the sagittal and superior temporal line in female skulls. An accurate map of the skull thickness representing the normative data of the studied population was developed. It is hoped that this topographic map will assist the surgeons in choosing the safest area of cranial bone graft harvest, thus increasing the safety of the procedure.

The Buccal Flap—A Useful Technique in Cleft Palate Repair?

Objective To evaluate speech quality and oronasal fistula after primary palate repair using a buccal mucosal flap. Design Retrospective study cohort of patients with cleft palate. Setting Primary care center for treatment of craniofacial congenital anomalies. Patients and Method One hundred fifty-six nonsyndromic patients underwent palatoplasty with the buccal myomucosal flap by the senior surgeon between 1989 and 2002. The preoperative workup, surgical technique, and other factors that might affect the outcome were identical in every case. Oronasal fistula and variables affecting speech quality were analyzed. Results The most common type of cleft was unilateral cleft lip and palate (43.5%). The median follow-up was 5.8 years (0.4 to 21 years), and the median age at repair was 6.2 months. The overall fistula formation was 3.6%, decreasing progressively: 1989 to 1994: 2.9%, 1995 to 2002: 0.7% (p < .05). Velopharyngeal incompetence (VPI) occurred in 8.8% of the patients, decreasing from 5.3% to 3.5% in the last years. VPI and oronasal fistulae were observed mainly in unilateral and bilateral clefts of the lip and palate. Velopharyngeal adequacy occurred in 91.1% of the children, and resonance was normal in 91.1 %. None of the patients had severe hypernasality or hyponasality. Articulation was normal in 97.9% of the children. Speech quality was good in 89% of the patients. Conclusions The technique presented has been effective, with the advantages of palatal closure without tension, good muscular reconstruction, lengthening of the nasal layer, and palatal closure without raw areas. The technique, early repair, and surgeons skills were the most important variables for good outcomes regarding speech and fistula formation.

Nasal augmentation with Surgicel-wrapped diced cartilage: a review of 67 consecutive cases.

Cartilage grafting has been used extensively to correct both the functional and aesthetic aspects of the nasal framework. The technique described by Erol ( 105: 2229, 2000) uses Surgicel-wrapped diced cartilage grafts in rhinoplasties. The advantages include its ease of preparation, the large volume of graft substrate available for use, and the avoidance of contour irregularities in the areas of placement. A retrospective case review of 67 consecutive patients who were treated with a Surgicel-wrapped diced cartilage graft as part of an aesthetic and/or functional rhinoplasty, in a 5-year period between 1995 and 2000, was performed in this study. All cases of congenital nasal deformities or deformities caused by trauma or tumors in which the technique was used were excluded. The charts were reviewed to determine demographic variables, the surgical procedures performed, prior operations, the rhinoplasty approach used, and the graft donor and recipient sites. Preoperative and postoperative photographs were examined, and the results were assessed. Data on the donor and recipient sites, complications, and the necessity for revisionary procedures were tabulated. There were two complications, namely, an infection, which resolved with aspiration and oral antibiotic therapy, and a recurrence of a dorsal depression, which necessitated repeated augmentation within 6 months. The technique of using Surgicel-wrapped diced cartilage proved to be effective for the augmentation of various areas of the nose. The complication and revision rates were acceptable and comparable to those of other techniques. Patient satisfaction with the aesthetic results was rated highly, with no reports of graft extrusion or contour irregularities. This technique is recommended for nasal augmentation and contouring for selected rhinoplasty patients.

Evaluation of 45S5 bioactive glass combined as a bone substitute in the reconstruction of critical size calvarial defects in rabbits.

Biomaterial research and tissue engineering have guided new developments in bone replacement. In this study, the osteoconductive and osteoinductive properties of 45S5 Bioglass® (Novabone-C/M®, Porex Surg., Newnan, GA), granules as a bone replacement material for large calvarial defects were evaluated. Rabbit periosteal cells were expanded in culture and used in vivo. Alkaline-phosphatase assay, collagen type I, and calcium expression were applied to confirm osteoblast phenotype. In the in vivo phase, a 15-mm diameter critical size calvarial defect was created in rabbits (n = 14). The defect was reconstructed according to four treatment groups: autogenous bone (n = 2), Bioglass alone (n = 2), Bioglass + bone (n = 5), Bioglass + periosteal cells (n = 5). The animals were killed 12 weeks after surgery, and the samples were analyzed. Periosteal cells grew successfully in vitro. Because of their fast proliferation and potential to differentiate into osteoblasts, they were an excellent source of cells for bone tissue engineering. The best ossification was seen when autogenous bone was used (79.4% ossified), whereas only 8.2% of the defect in the Bioglass group showed ossification. Addition of bone or cells to the Bioglass increased the area of ossification to 42.7% and 30.2%, respectively. Defects replaced with Bioglass showed varying degrees of inflammatory reaction because of the intense cell-mediated biodegradation process. Based on these findings, the use of Bioglass granules to repair large craniofacial defects cannot be advised.

Augmentation of the craniomaxillofacial region using porous hydroxyapatite granules

&NA; Augmentation of the craniomaxillofacial region is required for many aesthetic and reconstructive procedures. A variety of different materials and techniques have been used. Coralline hydroxyapatite has proved to have biocompatible properties as a bone graft substitute. This study further analyzes the use of porous coral‐derived hydroxyapatite granules in craniomaxillofacial augmentation for cosmetic and reconstructive purposes and evaluates the long‐term clinical result. This retrospective study reviewed the use of porous coral‐derived hydroxyapatite granules over a 20‐year period, between 1981 and 2001, in 180 patients, in whom 393 procedures were performed. The surgical technique is described and discussed. Statistical significance was evaluated by descriptive statistics and the correlation bivariate Spearmans test (p > 0.05). For 61.6 percent of the procedures, the surgical indication was reconstructive and in 38.4 percent, cosmetic. The maxilla was the most common site of surgery (44.3 percent), followed by the mandible (21.6 percent) and zygoma (15.4 percent). The complication rate was 5.6 percent (n = 22 of 393), with contour irregularities being responsible for 59 percent (n = 13 of 22). Both infection and granule extrusion were responsible for 1.3 percent of the complications. Good results were achieved in 96.4 percent of the procedures. Porous coral‐derived hydroxyapatite granules have shown considerable efficacy and versatility in craniofacial contour refinement and augmentation. They are stable, biocompatible, and safe. A sterile technique is advised, with care taken not to tear the periosteum in the pocket design and with subperiosteal placement of the granules, compaction of the granules at the site, overcorrection of 15 percent of the required total volume, watertight closure, and postoperative taping to prevent mobilization. The correct surgical indications and adherence to the principles stated above will result in a very satisfactory long‐term outcome. (Plast. Reconstr. Surg. 111: 1808, 2003.)

Repairing critical-sized rat calvarial defects with a periosteal cell-seeded small intestinal submucosal layer.

Background: Small intestinal submucosa was evaluated as a bioscaffold candidate for periosteum-derived osteoblasts, and its suitability as a bone replacement material for cranial defects was investigated. Methods: In the in vitro phase, osteoblasts were expanded in osteogenic medium and were then seeded onto small intestinal submucosa. To confirm osteoblast phenotype, they were tested for alkaline phosphatase, collagen type 1, and calcium expression. In the in vivo phase, calvarial critical-sized defects were created in 35 rats. The defects were either left untreated for surgical control (group 1), treated with small intestinal submucosa alone (group 2), treated with an osteoblast-embedded construct (group 3), or treated with an autogenous bone graft (group 4). The results were evaluated 12 weeks after surgery with radiopacity measurements and with stereologic analysis. Results: Periosteal cells grew successfully in vitro. The percentage radiopaque area at the defect was measured to be 42, 74, 76, and 89 percent for groups 1, 2, 3, and 4, respectively. The pixel intensity of the same site was 36.4, 48.1, 47.5, and 54.5 for the same groups, respectively. Tissue-engineered constructs did not achieve enough bone formation and calcification to be effective as autogenous bone grafts and were not superior to the small intestinal submucosa alone. However, both small intestinal submucosa and cell-seeded small intestinal submucosa showed significantly more bone formation compared with the untreated group. Conclusions: Although it was demonstrated that the small intestinal submucosa itself has osteogenic properties, it was not significantly increased by adding periosteum-derived osteoblasts to it. The osteogenic properties of small intestinal submucosa are promising, and its role as a scaffold should be investigated further.

Multicenter study of wound healing in neurofibromatosis and neurofibroma.

Based on clinical experience, the senior author has become convinced that wounds produced to correct the deformities of patients with neurofibromatosis (NF-1) have produced remarkably good scars, the interesting feature being that progression to keloid or hypertrophic scar is rare. The other point noted was that this situation did not change, no matter the patients race or skin color. There have been few reports describing or discussing this hypothesis. The purpose of this study was to investigate whether wounds produced in the patients with NF-1 produce keloid or hypertrophic scars. The patients with solitary neurofibroma were also included in this study; these were compared with the NF-1 group. This was conducted as a multicenter study. Patients with neurofibromatosis/solitary neurofibroma, who were operated on from 1990 to 2000, were evaluated by reviewing their medical charts and photographs retrospectively. The patients were treated in centers from five different countries. The analysis was undertaken based on the following points: 1) age and sex at surgery; 2) race of the patients; 3) past and family histories of hypertrophic scar and keloid; 4) surgical site(s); 5) diagnosis, NF1 or solitary neurofibroma; 6) surgical complications; 7) number of reoperations to manage the complications; 8) adjuvant therapy for the tumor; 9) depth of the tumors; and 10) incidence of malignant degeneration. A total of 101 cases with neurofibromatosis or solitary neurofibroma was analyzed. The age at surgery ranged from 1 year 6 months to 74 years; sex ratio was 47 males and 54 females. The racial distribution of the patients was 13 white, 13 black, 3 Hispanic, and 58 Asian. There was no past or family history of hypertrophic scar or keloid. The surgical sites were head and neck in 70 cases, trunk in 20 cases, upper extremities in 22 cases, and lower extremities in 20 cases. The clinical diagnosis was NF-1 in 57 cases, solitary neurofibroma in 35 cases, plexiform neurofibroma in four cases, and no distinct clinical diagnosis in five cases. There were no other types of neurofibromatosis. Hematoma and white wide scar were the main postoperative complications found in six cases of NF-1. Infection was also noted in four cases. However, no patient developed hypertrophic scar or keloid in the neurofibromatosis group, whereas two cases showed hypertrophic scar in the solitary neurofibroma group. The outcome showed that the patients with NF-1 and plexiform neurofibroma, no matter the racial group, produce good scars without keloid or hypertrophic changes, whereas solitary neurofibroma has a potential to cause hypertrophic scar.

Considerations surrounding reconstruction after resection of musculoskeletal sarcomas.

The defects left by resection of bone and soft-tissue sarcomas often require reconstructive surgery to provide adequate wound coverage, preserve limb function, and optimize cosmetic results. Immediate reconstruction should always be considered after resection with a negative margin, and should be attempted whenever possible. The choice of reconstructive method and tissue flap depends on multiple factors, including body site, donor site morbidity, functional requirements, size of the vascular pedicle, and aesthetics. Preoperative planning before the resection should anticipate the defect size and resulting functional and cosmetic deficits; the success of such planning depends on a collaborative approach between the teams performing the primary resection and the reconstruction. Vigilant postoperative care and flap monitoring is key to avoiding flap or graft failure, hematoma, infection, and other reconstruction-related complications.