Biomedical subjects

J A Fearon

Publications and source records attributed to J A Fearon.

15 recordsLinked to original sources

PubMed2001

The Le Fort III osteotomy: to distract or not to distract?

Treatment of the craniofacial dysostoses (e.g., Crouzon, Apert, Pfeiffer, Saethre-Chotzen syndromes) is critically dependent on the successful advancement of the midface with a Le Fort III procedure. The purpose of this retrospective clinical outcome study was to evaluate a new technique for distracting the Le Fort III procedure and to compare its results in growing children with those of the standard Le Fort III osteotomy. The records of 22 children were reviewed; 10 patients (mean age, 6.5 years) underwent a standard Le Fort III procedure, and 12 patients (mean age, 7.5 years) underwent a Le Fort III distraction procedure. The distraction group included two separate techniques, bilateral buried distraction (n = 2) and halo distraction (n = 10). Preoperative and 2- to 3-month postoperative cephalograms were analyzed. The average horizontal advancement achieved in the standard Le Fort III group was 6 mm, compared with 19 mm of advancement in the distraction group (p </= 0.005). Complications were evenly distributed between the two groups (one infection and one tracheostomy in each group), and the lengths of hospitalization were similar. No documented improvement in sleep apnea was identified in the standard Le Fort III group. However, in the distraction group two patients experienced normalization of sleep studies postoperatively as measured by respiratory disturbance index, and two patients underwent successful decannulation of tracheotomies. For aesthetic reasons, halo distraction was preferred over bilateral buried distraction. With halo distraction the vector of traction is focused in the facial midline, which helps to reposition the concave midface and to provide a more convex facial profile. In growing children, the ideal vector for distraction is determined by the malar position and not by dental occlusion. The amount of overcorrection can be calculated from tables of normal anthropologic data. On this preliminary review, it was concluded that the use of halo distraction, in combination with a modified Le Fort III osteotomy, provided a significantly further forward-positioned midface and seemed to offer a better correction of sleep apnea than did the standard Le Fort III osteotomy.

Cephalometry↗

PubMed2001

New methods for the evaluation and treatment of craniofacial dysostosis-associated cerebellar tonsillar herniation.

Herniation of the cerebellar tonsils may occur in children with craniofacial dysostosis (e.g., Apert, Carpenter, Crouzon, Jackson-Weiss, Pfeiffer, and Saethre-Chotzen syndromes), occasionally, with serious sequelae. Cerebellar tonsillar herniation is probably acquired in children affected with craniofacial dysostosis, raising the question, How should we be screening for this anomaly? This retrospective clinical study was undertaken to review the authors' series of what they believe to be a new surgical treatment for craniofacial dysostosis-associated cerebellar tonsillar herniation and to report their experience with a new screening technique. In an attempt to find a low-cost alternative to the use of routine magnetic resonance imaging for identifying cerebellar tonsillar herniation, the authors instituted sagittal reformatting of three-dimensional computed tomographic scans through the foramen magnum. Scans are considered positive if soft tissue is noted to extend below the foramen magnum, and all positive scans are further evaluated by magnetic resonance imaging with flow studies of the cerebrospinal fluid. These sagittally reformatted scans add no additional cost, and they seem to be highly sensitive in screening for cerebellar tonsillar herniation. Over a 13-month period, five children (one with Apert syndrome; four with Crouzon syndrome) with craniofacial dysostosis-associated cerebellar tonsillar herniation underwent isolated anterior cranial vault remodeling to treat observed brachycephaly (standard neurosurgical posterior decompression was not performed). All patients (mean age, 6 years; range, 2 to 14 years) were without the symptoms typically associated with cerebellar tonsillar herniation. Only those patients who had preoperative and postoperative magnetic resonance imaging scans were included in this review. All patients showed some improvement by the authors' magnetic imaging criteria after anterior cranial vault remodeling. Despite these findings, the authors recommend that until the anterior approach can be further studied, symptomatic children should undergo standard posterior neurosurgical decompression. The authors speculate that the presence of cerebellar tonsillar herniation may be a relative indication for decompressing the cranial vault in the craniofacial dysostoses. In addition, they propose that the descriptive anatomic term "cerebellar tonsillar herniation" be substituted for the misnomer "Chiari malformation" in these children.

Adolescent↗

PubMed2000

A magnetic resonance imaging investigation of potential subclinical complications after in situ cranial bone graft harvest.

The in situ harvest of cranial bone grafts, when assessed by clinical observation, has been shown to be a safe procedure when performed by experienced surgeons. However, might there be adverse sequelae from bone graft harvest that are not severe enough to produce observable changes and thus are missed by studies that rely on clinical outcomes? This study was designed to determine the incidence of "clinically silent" complications following routine bone graft harvest, such as punctate intracranial bleeding and cerebral contusions. This prospective clinical study included 20 patients. All patients had in situ cranial bone graft harvest performed by a single surgeon and underwent postharvest magnetic resonance imaging within 24 hours. Coronal computed tomographic scans were found to be the most helpful in the preoperative determination of donor sites. The average area of bone graft harvest was just under 14 cm2 (range, 3 to 30 cm2). No patients who had not previously undergone skull surgery were noted to have full-thickness breaches. Three patients identified with full-thickness breaches at surgery had harvest sites located in areas in which a previous craniotomy had occurred, suggesting that extreme care be used when harvesting bone from this subset of patients. All 20 postoperative magnetic resonance scans were reviewed by a neuroradiologist and determined to be completely normal. In conclusion, not only is in situ cranial bone graft harvest a safe procedure as assessed by clinical outcomes, but no subclinical complications were identified by post-operative magnetic resonance imaging.

Adolescent↗

PubMed1997

Infections in craniofacial surgery: a combined report of 567 procedures from two centers.

This retrospective review of infectious complications was undertaken at two craniofacial centers (Dallas and Philadelphia). Fourteen infections were identified over a 6.5-year period in 567 intracranial procedures primarily for craniosynostosis. There were no infections in infants under 13 months of age and no cases of meningitis. The overall infection rate was 2.5 percent, and 85 percent of infections occurred in secondary reoperative cases. Tracheostomies were not identified as a risk factor for infection. No difference was found in infection rates between patients with shaved and unshaved scalps. Candida and Pseudomonas were the two most common organisms identified, and 28 percent of our infections involved yeast. The average time to diagnose infection was 11.5 days (excluding three patients who averaged 5 months). Thirteen of the fourteen infections were treated surgically with placement of a subgaleal irrigation/drainage system. Initial bony debridement was kept to a minimum. Based on our findings, recommendations are made to further lower infection rates, particularly those caused by opportunistic organisms.

Antibiotic Prophylaxis↗

PubMed1996

Trigonocephaly-associated hypotelorism: is treatment necessary?

This study was designed to examine whether hypotelorism associated with trigonocephaly might be self-correcting. Only patients who required surgical treatment and had undergone preoperative and postoperative anthropometric measurements were included. In no case was any attempt made to correct the hypotelorism surgically. The study sample consisted of 16 patients, of whom 10 underwent preoperative and postoperative computed tomography in addition to anthropometric examinations. The results were compared with sex- and age-matched pooled normal standards, converted to standard Z scores, and analyzed by means of Student's t tests. Both intercanthal and interorbital widths increased significantly postoperatively, with improvements in delta Z scores of 0.445 (p < or = 0.01) and 0.638 (p < or = 0.05). These increases exceeded average growth increments by 1.6 mm for intercanthal width and 1.3 mm for interorbital width. Improvement in the intercanthal widths was significantly greater in the more severely affected children than in those whose conditions were less severe. A greater improvement in interorbital width also was noted in children treated at less than 6 months of age compared with those treated later. The younger the patient at surgery, the greater was the improvement, suggesting that early surgery may somehow release a constraint on interorbital growth.

Aging↗

PubMed1995

Transfacial approaches to the cranial base.

This article classifies and describes the anterior transfacial approaches to the cranial base as determined by the anatomic location of the lesions. With the use of craniofacial techniques, many of these lesions now may be resected without any significant functional or anesthetic morbidity.

Adolescent↗

PubMed1995

Observations on the use of rigid fixation for craniofacial deformities in infants and young children.

With the introduction of smaller plating systems, many surgeons have adopted their use for craniofacial procedures in infants and small children. We have encountered some previously undescribed problems associated with the use of plates and screws in infants and children. These problems can be classified into three general areas: 1) Plate displacement. This occurs after placement of the metal plates on the outside of the infant calvaria. With subsequent growth, these plates and screws may be found along the inner cortex of the skull with screw points embedded through dura. 2) Plate and screw isolation. In certain locations in young children, plates placed on the outer cortex of bone may later be found to be more prominent, isolated on a peninsula of bone. 3) Plate placement. We have also encountered plates that have been placed along the inner cortex of the skull during a previous operative procedure. This makes subsequent surgery extremely difficult and may increase the risk for secondary surgery. We propose that a previously described model for growth, involving areas of bony resorption and deposition, may be responsible for the observed plate displacement.

Bone Plates↗

PubMed1994

The coronal incision revisited.

The coronal scalp incision often leaves a noticeable scar causing the hair to part away from it, especially when wet. Changing the straight-line to a zigzag incision, called the stealth incision, eliminates this obvious deformity.

Child↗

PubMed1994

Comparison of craniofacial growth after rigid fixation with autogenous bone plates and with metal plates.

This study was undertaken to determine whether rigid fixation using autogenous cranial bone grafts restricts craniofacial growth less than metal plates in 7-week-old Yorkshire pigs. A rectangular 10 x 20 mm segment of bone centered on the right coronal suture was resected. Animals were randomly assigned to one of three experimental groups: (1) rigid fixation across the defect using the bone graft rotated 90 degrees and attached with four microscrews; (2) rigid fixation across the defect using two microplates attached with four microscrews; or (3) no rigid fixation, with four microscrews placed to serve as radiologic markers. All animals were followed up with serial radiographs, and 8 months after the surgery direct measurements were performed on dry skull preparations. The greatest lengths were in the control group, followed by the bone plate and then the metal plate groups, but these differences were not statistically significant. The cranial width was significantly greater in the bone plate group, suggesting that a growth center may have been reoriented.

Animals↗

PubMed1993

Massive teratomas involving the cranial base: treatment and outcome--a two-center report.

Massive teratomas involving the cranial base are extremely rare, and to our knowledge, there are no reports of this condition in surviving children. We describe the management of four cases of massive intracranial teratomas, reflecting a combined experience from two major referral centers. We found that when corrected at an early age, the brain parenchyma demonstrated a remarkable ability to reexpand in those children who had appeared to have sustained parenchymal deficits secondary to the mass effect from the tumor. Follow-up thus far suggests that regional skull growth potential may be compromised in some of these patients. Often, the exact pathologic diagnosis of these entities is somewhat different, since they may fall somewhere within the hamartoma-heterotopia-teratoma continuum. We believe that the best care of these children is offered through a combined simultaneous craniofacial and neurosurgical approach.

Child, Preschool↗

PubMed1993

Cranioscoliosis.

We have identified a particular facial asymmetry with unique characteristics that we call cranioscoliosis. Cranioscoliosis is a condition in which there is an apparent curvature of the midline of the cranial skeleton, cranial base, and facial skeleton when viewed in the axial plane. Cranioscoliosis is a diagnosis of exclusion. It is differentiated from the craniosynostoses by an absence of fused calvarial vault sutures. We recently developed a new technique, called cranial expansion, that involves interdigitating cuts in the calvaria which are subsequently expanded. We retrospectively reviewed the records of 13 patients identified as having this condition, of whom 7 were surgically treated. Our results seem to indicate that cranioscoliosis involves an inherent growth disturbance that does not appear to be corrected through any early surgical release.

Bone Transplantation↗

PubMed1993

Complications with facial advancement: a comparison between the Le Fort III and monobloc advancements.

Certain procedures for facial advancement may carry greater risk than others. While many believe that separating the cranial base by monobloc advancement leads to a higher complication rate, no comparative series between the Le Fort III and monobloc advancements has ever been reported. We reviewed our series of these different techniques. Over a 15-year period, 29 patients underwent 30 surgical procedures, with either a midfacial or frontofacial advancement. The average age of patients at the time of surgery was 12 years, with a range from 3 to 26 years. There were 20 Le Fort III and 10 monobloc advancements. Follow-up averaged 4 years, with a range from 10 weeks to 13 years. There were no deaths in this series. The infectious complications differed significantly between the two groups, with all major infections occurring in the monobloc group. The noninfectious complications (2 major and 20 minor) were proportionately distributed between the Le Fort III and monobloc groups. Aesthetic results of the midface, judged by the percentage of revisions necessary, were found to be the same between the two procedures. Aesthetic results were noted to correlate strongly with age at the time of surgery, with the older patients being judged as having a better aesthetic result and most of the younger patients requiring a repeat of the facial advancement. We conclude that while we were unable to determine any definitive aesthetic advantage of one procedure over the other in our series, there was a significantly higher infection rate with the monobloc advancement. On the basis of these results, we recommend a staging of the forehead and midfacial advancements.

Adolescent↗

PubMed1991

The skeletal treatment of orbital hypertelorism.

Orbital hypertelorism, strictly defined as an increase in bony interorbital distance, is not itself an isolated syndrome, but is instead an anomaly that may occur as either part of a syndrome or malformation sequence. Evaluation of orbital hypertelorism and the various anomalies that accompany it is best performed by a multidisciplinary craniofacial team. The timing of surgery involves considerations of multiple variables, but when performed can offer marked cosmetic improvements. Equally important as the skeletal surgery is correction of the associated soft-tissue problems.

Child↗

PubMed1990

Flap failure after microvascular free-tissue transfer: the fate of a second attempt.

In most cases, the loss of a free-tissue transfer is a disaster for both the patient and the surgeon. Seven patients received a second microvascular free-tissue transfer after loss of the first. The indications for free-tissue transfer included chronic osteomyelitis of the lower leg (four patients), acute traumatic defect of the leg (one patient), acute traumatic defect of the arm (one patient), and esophageal defect after surgical excision (one patient). In three patients, the interval between the first and second procedures was less than 2 weeks. The remaining four patients had their second free-tissue transfer performed 5 weeks to 21 months after the first. Six of the seven free flaps were successful. Two patients with venous obstruction occurring after the second free-tissue transfer were salvaged by reexploration. Partial loss of the flap was noted in one of these patients. It is concluded from this select group of patients that failure of a free-tissue transfer does not contraindicate a second microtissue transfer does not contraindicate a second microvascular free-tissue transfer.

Adolescent↗

PubMed1987

Midfacial duplication: a rare malformation sequence.

A child with duplicate maxilla is presented, along with a review of the literature of similar cases. Partial duplications of the maxilla are frequently accompanied by cleft lip and palate, multiple uvulae, hypertelorbitism, and intracranial anomalies with hydrocephalus. Theories of the morphopathogenesis for this malformation sequence are discussed.

Abnormalities, Multiple↗