Stereomicroscopy as a diagnostic aid in evaluating the viability of island flaps: an experimental study.

This study entailed direct stereomicroscopic observations of rat abdominal island flaps and the sequence of vascular events that occurred during and after occlusion by clamping of the individual femoral vessels for varying time intervals of up to 16 hours. The vascular changes and the status of the circulation in the flap vasculature, including the timing of complete hemal stasis and resumption of flow, following the application and subsequent release of the vessel clamp were observed and correlated with flap viability and behavior. This study also included a grading system of the vascular changes observed under a stereomicroscope. From these findings, it is suggested that in vivo stereomicroscopy may serve as a new and simple clinical tool for the early diagnosis of thrombosis at the site of microvascular anastomosis of a free flap transfer and may define time limits during which the anastomosis can be successfully corrected and the flap salvaged.

Critical closing pressure, local perfusion pressure, and the failing skin flap.

A simple apparatus was devised to perfuse the rat groin flap to study the relationship between perfusion pressure and flow. Results demonstrate that a relatively high intraarterial pressure must be applied to this skin flap before blood flow will commence. Results suggest that this critical closing phenomenon is the result of surface tension, blood rheology, venous pressure, tissue pressure, and vascular smooth muscle tone. Correlating the experiments of Milton and Landis reveals that, beyond a certain distance, local perfusion pressure in a skin flap gradually decreases with increasing distance from the flap base. These observations suggest that the perfusion boundary in a skin flap forms at the point where perfusion pressure has fallen to the level of the critical closing pressure. Methods of increasing survival length of a flap by decreasing critical closing pressure are discussed. The effects of edema and pressure dressings on flap and replant survival are examined in terms of the closing pressure concept.

Resection of a giant ossifying fibroma through an intraoral approach in a 9-year-old child: immediate reconstruction and 6-year cephalometric follow-up.

An unusual opportunity was afforded to study the growth and development of the facial structures of a 9-year-old child who underwent major mandibular reconstruction. The longitudinal studies confirmed the present concepts of the factors responsible for mandibular growth as well as their repercussions on other facial structures. An intraoral subperiosteal resection of a major portion of the right hemimandible sparing the upper part of the mandibular ramus was required to eradicate a large ossifying fibroma. An iliac bone graft consisting of the outer table of cortical bone and cancellous bone was placed within the mucoperiosteal sac to repair the defect. It also was used to control the ramus remnant. The patient was followed for 6 years. The growth of the reconstructed mandible was in effect nearly symmetrical with the unaffected contralateral portion of the mandible, resulting in minimal facial asymmetry. The mucoperiosteum provided a vascular bed for the bone graft and the buccal sulcus was preserved, thus providing a retentive ridge and sulcus for a denture without the need to perform a skin or mucosal graft inlay procedure. The symmetrical growth of the mandible is attributed to the growth of the ramus by remodeling, resorption, deposition, and relocation and by the muscle-bone interface (the functional matrix).

Early and late surgery in craniofacial dysostosis: a longitudinal cephalometric study.

Longitudinal clinical and cephalometric case studies are presented for two groups of patients with craniofacial dysostosis. The first sample includes two infants who underwent an extensive stripping procedure that was extended inferiorly to involve not only the coronal, but also the sphenozygomatic suture. The second sample includes two adolescents with midfacial hypoplasia who underwent a fronto-orbital-maxillary advancement. The extensive cranial stripping procedure had a favourable impact upon growth and development of the craniofacial structures, and longitudinal studies suggest the importance of promoting the growth potential of the bones contiguous to the affected sutures. Craniofacial surgery performed on adolescents results in a dramatic translocation of the skeletal and soft-tissue structures of the face. In contrast to early surgical intervention in infants in whom growth of the effected areas essential to the development of face and cranium was crucial, late surgery appeared to have little, if any, impact upon the development of the craniofacial skeletal structures that had been operated on.

The major histocompatibility complex (HLA) as a genetic marker in human craniofacial anomalies.

Study of the incidence and segregation of the serologically detectable A and B products of the HLA complex in 140 family units in which one or more offspring was afflicted with a developmental craniofacial anomaly has uncovered no evidence of an association between HLA-A or B antigens or haplotypes and the malformations under study. Further analysis of HLA-D products in the same family units by the mixed leukocyte culture (MLC) technique has, however, uncovered a relatively high incidence of non-reactivity between the cells of one (or both) parent(s) and cells of some offspring in 41 of the 140 families included in this study. The parent couples involved in this finding were unrelated and generally did not share any HLA-SD haplotypes. When this finding was studied further by Primed LD Typing techniques, the results in six families suggested that such MLC non-reactivity is a consequence of the sharing of LD alleles by each pair of parents in these families. The known polymorphism of the HLA-D locus (or loci) and the low incidence of comparable findings in the normal population suggest that LD allele sharing in this particular population may be related to the selection of certain particular HLA-D products in families afflicted with developmental craniofacial anomalies. This result may be relevant to the possible existence in man of an analogue of the murine T/t complex which may occur in linkage with the HLA complex, in the same manner as the linkage disequilibrium which is been documented between the t complex and H-2 in chromosome 17 of the mouse.

Conservation of major leg arteries when used as recipient supply for a free flap.

The potential hazards of using proximal segments of leg arteries for end-to-end anastomosis to vessels in free flaps are examined, and alternatives are proposed. The convservation of the major tibial arteries seems highly desirable, to minimize any subsequent development of ischemic complications. Turning a free flap upside down moves the anastomosis to the distal part of the extremity, thus conserving most of the muscular branches of the recipient artery. Cutting the recipient artery distally and bending it back in recurrent fashion also allows for easy end-to-end anastomosis, with many technical advantages.

Correction of protruding ears: A 20-year retrospective.

Twenty years experience with the tubing technique has proved it to be reliable and adaptable to the usual abnormalities associated with the protruding ear. The technique is especially dependable when all components of the auricle are involved, when the antihelical fold is absent, and there is a large or protruding concha. The recurrence rate of 2.6% is quite acceptable when compared with other techniques.

Correction of enophthalmos by disentrapment of an orbital blow-out fracture: case report.

We present a case of enophthalmos from a posterior orbital blow-out fracture. The entrapped tissues were released surgically, resulting in disappearance of the enophthalmos and restoration of ocular motility.

Surgical correction of the facial deformities of acromegaly.

The neurosurgical treatment of acromegaly is well established, but little has been written about correction of the facial deformities of this disease. Although hypertrophy of the skin and subcutaneous tissues may decrease after successful treatment of the pituitary tumor, there is no reversal of the bony changes. An acromegalic patient is presented whose facial deformities were repaired in stages by mandibular osteotomy and soft tissue excision. The history and pathology of acromegaly are reviewed.