Re: invited discussion. Role of three-dimensional computed tomography in the asessment of nasoorbitoethmoidal fractures.
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Biomedical subjects
Publications and source records attributed to D Remmler.
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OBJECTIVE: We report the successful use of a Furlow palatoplasty to salvage velopharyngeal competence following iatrogenic avulsion of a pharyngeal flap that had been previously established to treat velopharyngeal insufficiency associated with a submucous cleft palate. INTERVENTION: A tonsillectomy, conducted by a surgeon unaffiliated with a cleft palate team, was used to remove enlarged tonsils that had developed after pharyngeal flap surgery and extended into the lateral ports causing nasal obstruction and hypernasality because of mechanical interference with port closure. A posttonsillectomy evaluation revealed avulsion of the pharyngeal flap, which was successfully treated using a Furlow palatoplasty. CONCLUSIONS: To our knowledge, this is the first report of iatrogenic avulsion of a pharyngeal flap caused by tonsillectomy. Based on a review of the literature and this case experience, we would conclude that tonsillectomy should not be regarded as a routine procedure in patients previously treated with a pharyngeal flap. If required, it should be performed by a skilled otolaryngologist, preferably one affiliated with a multidisciplinary cleft palate team who is familiar with pharyngoplasty surgery. Finally, our experience would suggest that the Furlow palatoplasty is sufficiently robust to be used as a secondary salvage procedure to restore velopharyngeal sufficiency following iatrogenic avulsion of a pharyngeal flap.
Successful management of nasoorbitoethmoidal (NOE) fractures requires early diagnosis and accurate determination of the extent of injury. Although the anatomic complexity of the NOE region merits a clear interpretation of the spatial relationships associated with each injury, the role of three-dimensional (3D) computed tomography (CT) in the assessment of these fractures remains unclear. To clarify the diagnostic value of 3D CT, this retrospective analysis compares statistically the accuracy of two-dimensional (2D) CT against 3D CT in the detection of NOE fracture line tracts in 21 consecutive patients with surgically confirmed NOE fractures. Accuracy of radiographic findings of both modalities were compared with intraoperative findings serving as the "gold standard" for detecting fracture lines in NOE fractures. This statistical analysis indicates that combining 3D CT and 2D CT produces a higher diagnostic yield in the evaluation of NOE fractures than using either modality alone. Although 2D CT was significantly superior (p < 0.05) for inspection of the medial orbital wall, 3D CT offered significantly greater diagnostic accuracy (p < 0.05) along the medial maxillary buttress, particularly at the piriform aperture. 3D CT clarified spatially several unusual NOE injuries that were indiscernible with 2D CT alone. We recommend the combination of 3D CT with 2D CT for serious NOE injuries, particularly those involving displacement of the NOE complex or associated with other major midfacial fractures.
Recently, surgeons have begun to treat serious congenital craniofacial deformities including craniosynostoses with mechanical devices that gradually distract the skull. As a prospective means of treatment planning for such complex deformities, FE models derived from routine preoperative CT scans (CT/FEA) would provide ideal patient specific engineering analyses. The purpose of this study was to assess the dimensional and predictive accuracy of the CT/FEA process through the development of a 3D model of a dry human calvarium subjected to two-point distraction ex vivo. Comparative skull measurements revealed that CT/FEA construction error did not exceed 1% for transcranial dimensions, and the thickness error did not exceed 8.66% or 0.31 mm. CT/FEA strain predictions for the central region of the skull, between the distraction posts, were not statistically different from homologous gage values at P < 0.05. Peripherally, however, the strain fields were less well behaved and the FE predictions showed only general qualitative agreement with gage recordings.
Finite element analysis from routine computed tomography studies (CT/FEA) allows clinicians to predict the mechanical and anatomic consequences of specific distraction systems before human application. A realistic three-dimensional CT/FEA engineering model of an actual plagiocephalic infant with unicoronal synostosis was developed using 4215 parabolic triangular shell elements and intracranial pressure conditions ranging from 10 to 20 mmHg. The completed finite element analysis model was used to predict the anatomic outcome of multiaxial distraction delivered by hypothetical patterns of rod and node distraction units. The predictions for the various patterns of distraction units were also compared quantitatively with respect to force, stress, strain, and intracranial volume. Best anatomic corrections were achieved with bilateral patterns of distraction units that simultaneously elongated the ipsilateral cranium and shortened the contralateral cranium. Greatest strain levels were experienced within the osteotomy callus, greatest stress levels at the appliance anchorage sites, and the greatest rod force at the ipsilateral lower coronal position.
A study of cranial vault lengthening using a custom expandable fixation-distraction (craniotatic) appliance was performed in the young-adult rabbit model. Ten 24-week-old rabbits underwent circumferential suturectomy plus expansion (expanded group), 10 underwent circumferential suturectomy without expansion (sham control group), and 10 served as normal controls. The appliance was lengthened at a rate of 2.5 mm per week for 5 weeks. Serial lateral cephalometry, comparative dry-skull anthropometric measurements, and histologic examinations were performed. The expanded group demonstrated a significantly longer skull, cranial vault, anterior cranial base, posterior face, and orbit as compared with the control groups (p less than 0.05). Callus bone filled the distracted suturectomy and united the frontofacial complex to the posterior cranium. In conclusion, skull lengthening by distraction osteogenesis is possible in the rabbit model and offers a new technique for future investigation in the treatment of coronal synostosis.
Large quantities of cultured human facial dermal fibroblasts were propagated from randomly selected patients to determine their relative suitability as percutaneously injectable living implants. Volumetric and histologic comparisons were made between the following implants that were injected subcutaneously into athymic nude mice: (1) cultured human fibroblasts (HFb); (2) cultured human fibroblasts dispersed in Zyderm II collagen (HFb + Zyd); (3) Zyderm II collagen (Zyd); and (4) Zyplast collagen (Zyp). Both the HFb and HFb + Zyd implants were accepted as primary takes but regressed volumetrically at significantly greater rates than either the Zyd or Zyp implants. Correlative immunohistochemical staining revealed that, by 10 days, 90% of the cells within the HFb implants and 80% within the HFb + Zyd implants were of human origin; however, by 9 weeks, approximately 25% of the cells were of human origin in both types of implants. These results indicated that cultured human fibroblasts can be successfully injected as living grafts; however, the subsequent gradual attrition in the numbers of implanted cells, as noted in this model system, limits the long-term retention of the implants.
Merkel cell carcinoma, also known as endocrine carcinoma of the skin, is a recently recognized and particularly aggressive form of skin cancer that exhibits histologic features similar to those of endocrine malignant neoplasms arising from other tissues. Forty-one patients with Merkel cell carcinoma arising from the cutaneous surfaces of the head and neck were seen at the University of Texas M. D. Anderson Hospital, Houston, between 1966 and 1983. Regional lymph node metastasis occur early and frequently, with a 79% overall incidence observed during the course of the disease. Treatment should consist of a wide resection of the primary tumor. A regional lymphadenectomy, when feasible, is successful in controlling nodal metastases. Postoperative radiation is recommended as an important adjuvant.
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Frontal sinus infections can spread to the intracranial space so fast that the clinical situation often becomes far advanced before a complication is recognized. Retrograde septic thrombophlebitis is the most common pathway of extension. A review of recent experiences with fulminating frontal sinusitis and its intracranial complications such as subdural empyema, brain abscess, epidural abscess, and meningitis is presented. Neurologic features of intracranial invasion are interpreted. Good results have been achieved by immediate and aggressive surgical and medical measures.
The records of 160 patients with squamous cell carcinoma of the tonsillar fossa treated from 1968 through 1979 were reviewed. Biologic behavior, local and regional findings, and other prognostic factors were evaluated. patients were treated by either radiation alone (112 patients), radiation followed by planned neck dissection (31 patients), surgery alone (11 patients), or surgery combined with radiation (6 patients). Analysis of the data supports the recommendation that radiation be used as treatment for T1, T2, and early T3 lesions, whereas surgery alone or combined with radiation is best employed for advanced T3 or T4 tumors. Primary tumor control rates with radiation as the initial modality were 100% for T1 lesions, 89% for T2, 68% for T3, and 24% for T4. In addition, the control of cervical metastases with radiation therapy for patients with neck disease staged N0 through N3b was excellent (95%). In instances where a planned neck dissection was done 5 weeks after radiation, the control of cancer in the neck was 100%. The incidence of distant metastases was 10% and was not affected by the selection of therapy. The 2- and 5-year determinate survival figures for 112 patients treated with radiation therapy alone was 67% and 48% respectively, while 31 patients treated with radiation therapy followed by neck dissection achieved survival rates of 70% (2 year) and 58% (5 year). The criteria for selection of treatment are discussed.
A prospective longitudinal study of shoulder function after 103 neck dissections involving either preservation or sacrifice of the spinal accessory nerve is presented. The postoperative evolution and course of trapezius muscle denervation and resultant shoulder dysfunction were objectively determined for both radical and modified nerve sparing neck dissections. All patients were enrolled in a program of physical therapy aimed at maintaining range of motion at the shoulder joint. Shoulder function was examined preoperatively and for 12 months postoperatively with manual muscle strength testing, range of motion measurements, and electrodiagnostic testing. Results indicate that modified nerve sparing dissections are followed on the average by a significant, but temporary and reversible phase of shoulder dysfunction. By comparison, radical neck dissection is followed by profound and permanent trapezius muscle weakness and denervation.