Henry K. Kawamoto

Human NELL-1 expressed in unilateral coronal synostosis

Surgical correction of unilateral coronal synostosis offers a unique opportunity to examine the molecular differences between an abnormal and a normal cranial suture. We isolated and identified a cDNA fragment whose expression was up‐regulated in the premature fusing and fused coronal sutures, as compared with normal coronal sutures. The nucleotide sequence of the full‐length cDNA of this gene, human NELL‐1, has ∼61% homology with the chicken Nel gene. Both chicken Nel and human NELL‐1 are comprised of six epidermal growth factor‐like repeats. The human NELL‐1 messages were localized primarily in the mesenchymal cells and osteoblasts at the osteogenic front, along the parasutural bone margins, and within the condensing mesenchymal cells of newly formed bone in sites of premature sutural fusion. Human multiorgan tissue mRNA blot showed that NELL‐1 was specifically expressed in fetal brain but not in fetal kidney, liver, or lung. We also showed that Nell‐1 was expressed in rat calvarial osteoprogenitor cells and was largely absent in rat tibiae and fibroblast cell cultures. In conclusion, our data suggest that the NELL‐1 gene is preferentially expressed in cranial intramembranous bone and neural tissue (both of neural crest cell origin) and is up‐regulated during unilateral premature closure of the coronal suture. The precise role of this gene is unknown.

Late posttraumatic enophthalmos: a correctable deformity?

Long-established posttraumatic enophthalmos with a seeing eye is a correctable deformity. A method utilizing principles of craniofacial surgery is described that provides the advantages of (1) wide exposure, (2) free mobilization of the displaced zygoma, (3) direct inspection of the orbital defect, and (4) restoration of the balance between the orbital contents and bony surroundings, which allows (5) the permanent correction of traumatic enophthalmos using autogenous material.

Repair of Alveolar Cleft Defects: Reduced Morbidity With Bone Marrow Stem Cells in a Resorbable Matrix

Harvest of the autogenous iliac crest bone graft for an alveolar cleft defect (the gold standard) may cause short- and long-term pain and sensory disturbances. To determine if a tissue engineering technique with similar bone healing results offered decreased morbidity, we compared techniques for postoperative donor site pain. Traditional iliac crest bone graft had more donor site complications compared with both tissue engineering and minimally invasive iliac crest bone graft. With donor site pain, traditional had the most patients with pain and tissue engineering had the least patients with pain at all time points. The mean pain score, including both intensity and pain frequency, was greatest at all time points in traditional and least at all time points in tissue engineering. Closure of alveolar cleft defects with a resorbable collagen sponge and bone marrow stem cells resulted in reduced donor site morbidity and decreased donor site pain intensity and frequency.

Monobloc advancement by distraction osteogenesis decreases morbidity and relapse

Background: Treatment of midface hypoplasia and forehead retrusion with monobloc advancement is associated with significant complications, including meningitis, prolonged intubation, and frontal bone flap necrosis. To see whether distraction of the monobloc segment offered decreased morbidity, the authors compared clinical outcomes of patients who underwent conventional monobloc advancement with those of patients who underwent monobloc distraction. Methods: Group 1 (conventional monobloc; n = 12) underwent traditional monobloc advancement with bone grafting. Group 2 (modified monobloc; n = 11) did not receive ventriculoperitoneal shunts and underwent the above procedures with placement of a pericranial flap and fibrin glue over the midline defect. Group 3 (monobloc distraction; n = 24) underwent advancement of the monobloc segment by distraction osteogenesis using internal distraction devices. Complications included meningitis, cerebrospinal fluid leak, frontal bone flap loss, and wound infection. Preoperative, postoperative, and follow-up lateral cephalograms were used to assess horizontal changes of the forehead, midface, and maxilla. Results: Group 3 (distraction monobloc) had the lowest complication rate (8 percent), followed by groups 2 (modified monobloc; 43 percent) and 1 (conventional monobloc; 61 percent) (p < 0.05). Group 3 achieved greater advancement (12.6 mm) than did group 2 (9.4 mm) or group 1 (9.1 mm) (p < 0.05). Relapse was least in group 3 (8 percent) compared with groups 2 (67 percent) and 1 (45 percent). Conclusions: Monobloc advancement by distraction osteogenesis had less morbidity and achieved greater advancement with less relapse compared with conventional methods of acute monobloc advancement with bone grafting. Monobloc distraction is superior to conventional methods of acute monobloc advancement and is an alternative to staged fronto-orbital advancement followed by Le Fort III advancement.

Successful blood conservation during craniosynostotic correction with dual therapy using procrit and cell saver.

Background: Craniosynostotic correction typically performed around infant physiologic nadir of hemoglobin (approximately 3-6 months of age) is associated with high transfusion rates of packed red blood cells and other blood products. As a blood conserving strategy, we studied the use of 1) recombinant human erythropoietin or Procrit (to optimize preoperative hematocrit) and 2) Cell Saver (to recycle the slow, constant ooze of blood during the prolonged case). Methods: UCLA Patients with craniosynostosis from 2003-2005 were divided into 1) the study group (Procrit and Cell Saver) or 2) the control group (n = 79). The study group 1) received recombinant human erythropoietin at 3 weeks, 2 weeks, and 1 week preoperatively and 2) used Cell Saver intraoperatively. Outcomes were based on morbidities and transfusion rate comparisons. Results: The 2 groups were comparable with regards to age (5.66 and 5.71 months), and operative times (3.11 vs 2.59 hours). In the study group there was a marked increase in preoperative hematocrit (56.2%). The study group had significantly lower transfusions rates (5% vs 100% control group) and lower volumes transfused than in the control group (0.05 pediatric units vs 1.74 pediatric units). Additionally, of the 80% of patients in the study group who received Cell Saver blood at the end of the case, approximately 31% would have needed a transfusion if the recycled blood were unavailable. Conclusion: Our data showed that for elective craniosynostotic correction, successful blood conserving dual therapy with Procrit and Cell Saver might be used to decrease transfusion rates and the need for any blood products.

Correction of major defects of the vermilion with a cross-lip vermilion flap.

A method is described to correct major vermilion defects by using a transverse, cross-lip, vermilion flap. Sizable defects can be easily filled in to obtain an upper lip with better contour and simultaneously reduce the unpleasant fullness of the lower lip to produce better balance between the two lips.

Improved outcomes in cleft patients with severe maxillary deficiency after Le Fort I internal distraction

Background: Correction of severe maxillary deficiency in cleft lip–cleft palate patients often results in undercorrection, relapse, and need for secondary corrective procedures. Le Fort I internal distraction osteogenesis offers an alternative to one-step orthognathic advancement, with advantages of gradual lengthening through scar and earlier treatment in growing patients. Methods: Patients with cleft lip–cleft palate deformities and maxillary deficiency were divided into three groups treated by Le Fort I advancement: group 1, mild to moderate deficiency (<10 mm) with conventional orthognathic procedure; group 2, severe deficiency (≥10 mm) with conventional orthognathic procedure; and group 3, distraction procedure for severe deficiency (≥10 mm) (n = 51). Preoperative, postoperative, and follow-up (>1 year) lateral cephalogram measurements were compared including angular (SNA and SNB) and linear (&Dgr;x = horizontal and &Dgr;y = vertical) changes. The Pittsburgh Speech Score was used to assess for velopharyngeal insufficiency (score >3). Results: Results demonstrated that group 1 patients had a mean SNA change from preoperatively (78.7) to postoperatively (83.8), and a horizontal change of 5.0 mm, with no relapse. Group 2 patients had a mean SNA change from preoperatively (76.3) to postoperatively (82.0) and a horizontal change of 7.2 mm, with 63 percent relapse. Group 3 patients had a mean SNA change from preoperatively (74.1) to postoperatively (84.9) and a horizontal change of 16.5 mm, with 15 percent relapse. Thus, for severe maxillary deficiency, the distraction group had 48 percent less relapse than the conventional Le Fort I group. Postoperative speech evaluation showed velopharyngeal insufficiency in the following: group 1, four of 20 patients (20 percent); group 2, nine of 11 patients (82 percent); and group 3, nine of 20 patients (45 percent). Conclusion: These data suggest that Le Fort I internal distraction for severe cleft maxillary deficiency leads to better dental occlusion, less relapse, and better speech results.

The effect of rigid internal fixation on cranial growth

As the use of rigid internal fixation of the facial skeleton has become routine in adults, many craniofacial surgeons have expanded its use to the pediatric population. The effects of miniplate and screw fixation on subsequent craniofacial growth, however, have not been examined. Using 6-week-old rabbits as an experimental model, miniplates were placed across the right coronal suture. Calvarial changes were measured by direct osteometry on dry skull preparations. Compared with the control group, a significant reduction in growth was noted across the plated suture and adjacent bones. Because secondary growth disturbances can be produced with the use of these fixation devices, their use in the pediatric population should be viewed cautiously.

Primary and secondary orbit surgery: the transconjunctival approach.

The transconjunctival approach to the orbit is underutilized because of concern regarding inadequate exposure and higher postoperative rates of lower eyelid shortening and ectropion. All patients who had a transconjunctival incision performed for orbital surgery over the last 6 years (1990 to 1996) were studied. Patients who had a transconjunctival blepharoplasty were excluded. A total of 35 patients, average age 32 years, had 45 transconjunctival incisions performed. Lateral canthotomy or cantholysis was not done. Operations fell into three categories: fracture plating alone, 10 (22 percent); split-calvarial bone graft placement with or without plating, 26 (58 percent); and orbital decompression, 9 (20 percent). The overall incidence of ectropion was 6.7 percent (3 of 45). One patient (2 percent) had transient ectropion, and two patients (4 percent) had persistent ectropion, which required surgical correction. Ectropion occurred only in those lower eyelids that had a previous transcutaneous incision (3 of 18 = 17 percent). None occurred in those eyelids that had no prior incision or only a previous transconjunctival incision. The transconjunctival approach without a lateral canthotomy provides safe access to the orbit in eyelids that have not had a previous transconjunctival incision.

Rare craniofacial clefts: Tessier no. 4 clefts.

A major difficulty in understanding rare craniofacial clefts arises from the fact that previous reports have focused on a single case or have grouped together different types of rare clefts. Less than 50 Tessier no. 4 clefts have been reported. This paper examines our experience with eight patients treated primarily or secondarily for Tessier no. 4 clefts. A treatment plan is recommended. The primary early concern is protection of the eye. Early correction of soft issue deformities should include skin, muscle, and lining of the orbit, cheek, and oral cavity. Contrary to the dictum that all soft tissue must be preserved, the medial portion of the upper lip from the cleft to the philtral ridge must be resected to prevent poorly camouflaged scars, muscle deficiency, and macrostomia. Bone grafting should be undertaken at an early age using calvarial bone. Late operations will be necessary for correction of medial and lateral canthal position, epiphora, lower eyelid skin deficiency, and further bony augmentation.