The influence of external ultrasound on the histologic architecture of the organic capsule around smooth silicone implants: experimental study in rats.

BACKGROUND: Capsular contracture is the main complication related to breast silicone implants, and its prevention remains a medical challenge. The authors present experimental research examining the effect of external ultrasound on the formation and contracture of peri-implant capsules. METHODS: In this study, 42 male Wistar rats had a 2-mm smooth surface implant placed in a dorsal submuscular pocket. They then were separated into "ultrasound" and "control" groups that received repeated external applications either with or without the ultrasound power on. Ultrasound applications were given three times a week for a period of 90 days. After that, both groups were housed under the same conditions with no application scheduled. Five animals of each group, killed at 30, 60, 90, and 180 days, had their implants removed along with the capsule, which received a special histologic preparation via annular sectioning that provided wide circumferential observation of the capsular tissue. Sections were stained with hematoxylin/eosin stain, Masson's trichrome stain, and Pricrosirius Red stain for regular microscopic evaluation under normal and polarized light. RESULTS: Histologic data showed that capsules from the ultrasound and control groups had statistically significant differences. Ultrasound application developed a capsular architecture similar to that shown within textured silicone implants, and its effect had an early definition with subsequent stabilization. CONCLUSION: The authors conclude that early and repeated external ultrasound application enhances the thickness, cellular count, and vascularity of smooth silicone capsular tissue, whereas it diminishes the pattern of parallel orientation of collagen fibers.

End-to-side neurorrhaphy with and without perineurium.

OBJECTIVE: We compared end-to-side neurorraphy with and without the perineural sheath. METHOD: Twenty rats were used. The peroneal nerve was sectioned and the distal end was sutured to the lateral face of the tibial nerve. We removed the perineural sheath only on the right side, but not on the left side. The proximal end of the peroneal nerve was curved back approximately at a 100 degrees angle and implanted into the adductor muscle. Six months later, the 14 surviving animals were submitted to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. RESULTS: On the right side, the muscles that had positive response needed an average of 258.89 mV (+/- 92.31) of electric stimulus and on the left side 298.34 mV (+/- 139.32). The average weight of the tibial cranial muscles of the right side was 0.47 g (0.18) and for the left side 0.45 g (0.15). The distal end of the peroneal nerve showed averages of 310.29 (+/- 191.34) nerve fibers on the right side and 287.71 (+/- 183.60) on the left side. The tibial nerve above the neurorraphy showed averages of 939.46 (+/- 223.51) nerve fibers on the right side and 959.46 (+/- 327.48) on the left side. The tibial nerve below the neurorraphy showed averages of 935.17 (+/- 298.65) nerve fibers on the right side and 755.31 (+/- 323.26) on the left side. The average areas of the right tibial cranial muscles were 0.0162 m2 (+/- 0.008), after 230 magnification, and 0.0152 m2 (0.0064) for the left tibial cranial muscles. The histological features of the tibial cranial muscles, taking normal as 100%, were 78.21 (+/- 20.75) on the right side and 82.14 (+/- 15.89) on the left side. The statistical analysis (Student's t test) did not reveal any difference (p > 0.05) among right and left sides for all variables. CONCLUSION: The authors concluded that the two neurorraphies (with and without perineurium) did not show any difference regarding morphological and electrophysiological features studied.

Apert's syndrome: modification in corrective techniques.

While the osteotomy techniques for craniofacial synostosis treatment are well-known and frequently used, the resolution of the nasal air impairment, ocular prolapse, and retromaxillism relapse remains unsatisfactory. The modification of the osteotomy presented here has the purpose of a new therapeutic trial.

Reparation of peripheral nerves with fibrin glue prepared from snake venom. Preliminary results.

A new fibrin glue obtained from snake venom is presented, with possible utilization in various fields of medicine. The preparation procedures and tests in the reparation of peripheral nerves are described. The preliminary results were similar to the conventional fibrin glue procedure.

New option for anterior traction of the face by using a cervical collar.

This case required anteroposterior traction of the maxilla. Once none of the traditional methods could be used because of the lack of support in the chin and in the frontal region. Thus, we opted to use a cervical collar.

Cranioplasty: the autograft option.

We present our clinical experience in cranioplasty with autograft as follows: conchal cartilage for losses up to 2 cm2, outer table grafts for defects up to 100 cm2, and, for larger defects still, split rib grafts, which may be combined with outer table grafts. We conclude that autograft is superior to alloplastic material in cranioplasty.

End-to-side neurorrhaphy with removal of the epineurial sheath: an experimental study in rats.

Terminolateral neurorrhaphies were used up to the beginning of this century. After that, they were no longer reported. We tested the efficacy of a new type of end-to-side neurorrhaphy. A group of 20 rats had the peroneal nerve sectioned, and the distal ending was sutured to the lateral face of the tibial nerve after removing a small epineural window. All experiments were made on the right side, the left one remaining untouched in half the animals of each group. The other half was denervated by sectioning and inverting the endings of the peroneal nerves. In this way, tibial cranial muscles were either normal or denervated on the left side and reinnervated through end-to-side neurorrhaphies on the right side. After 7.8 months, the animals were subjected to electrophysiologic tests, sacrificed, and the nerves and muscles were taken for histologic examination. A response of the tibial cranial muscle was obtained in 90 percent of the animals. The distal ending of the peroneal nerve showed an average of 861 nerve fibers. The average areas of the reinnervated tibial cranial muscles were (microns 2) 1617.81 for M2n (when the contralateral side was normal) and 1579.19 for M2d (when the contralateral was denervated). We conclude that the terminolateral neurorrhaphy is functional, conducting electrical stimuli and allowing the passage of axons from the lateral surface of a healthy nerve, to reconstitute the distal segment of a sectioned nerve. The absence of an incision on the axons of the donor nerve was no impediment to axonal regeneration or to the passage of electrical stimuli. The results demonstrate the possibility of using end-to-side and terminolateral neurorrhaphies for reconstituting neural lesions when only a distal end is available; the reinnervation can be obtained from the lateral face of a healthy nerve.

Facial bone lengthening apparatus with expander and miniplates.

Since 1869, bone lengthening has been pursued; when Langenbeck tried growing a shortened bone extremity utilizing for this an arteriovenous fistula in the thigh. At the beginning of this century, codovilla (1905) introduced bone lengthening methods for lower limbs.

Fat-tissue injection versus graft: experimental study in rabbits.

An experimental study of fat-tissue implants in the ears and frontal regions of rabbits was conducted, starting with blocks of tissue for surgical implantation or with multifragmented pieces for injection. The implants were observed from day 7 to month 12. Low integration levels were observed in all animals, except for 1 case that had 20% and 42% of integration, respectively, for the block grafts and for the injected multifragmented tissue.

Two end-to-side neurorrhaphies and nerve graft with removal of the epineural sheath: experimental study in rats.

We have studied a new type of end-to-side nerve repair in rats. The healthy (donor) nerve was not divided but an epineural window was created. In our experiment, a nerve graft bridged the tibial nerve to the distal end of the divided peroneal nerve. Electrophysiological studies showed electrical impulses conducted through both end-to-side nerve junctions. Histological studies demonstrated axons leaving the lateral surface of the healthy (donor) nerve. Based on these observations, we suggest that end-to-side neurorrhaphy from a healthy nerve may bridge a neural deficit.

Histological and radioisotopical analysis of the skull graft: an experimental study in rabbits.

The purpose of this study was to develop an experimental model in rabbits that would permit us to analyze skull reconstruction and enable the study of bone autografts, osteofacial flaps, and other materials. We use the rabbit model to study the early integration of the skull autograft and to demonstrate the relationship between radioisotopical and histological analyses.

Latero-terminal neurorrhaphy without removal of the epineural sheath. Experimental study in rats.

Termino-lateral neurorrhaphies have been used up to the beginning of this century. After this period, they have no longer been reported. We tested the efficacy of a new type of latero-terminal neurorrhaphy and evaluated the role of the epineural sheath. A group of 10 rats had the fibular nerve sectioned and the distal ending was sutured to the lateral face of the tibial nerve without removing the epineurium. All experiments were made on the right side, the left one remaining untouched in half of the animals of each group. The other half were denervated by sectioning and inverting the endings of the fibular nerves. In this way, tibial cranial muscles were either normal or denervated in the left side and reinnervated through latero-terminal neurorrhaphy in the right side. After 7.7 months, the animals were subjected to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. A response of the tibial cranial muscle was obtained in 75% of the animals. The distal ending of the fibular nerve showed an average of 498 nerve fibers. The average areas of the reinnervated tibial cranial muscles were (mu 2):841.30 for M2n and 1798.33 for M2d. We concluded that the termino-lateral neurorrhaphy was functional, conducting electrical stimuli and allowing the passage of axons from the lateral surface of a healthy nerve, to reconstitute the distal segment of a sectioned nerve. The presence of the epineurium was no impediment to axonal regeneration or to the passage of electrical stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)

Trigonocephaly.

Trigonocephaly has been described either as an isolated anomaly or as part of the clinical spectrum of some well-known syndromes. Treatment, complications, and prognosis are closely related to the manifestations of the associated anomalies. We report on the main types of syndromes with trigonocephaly and the management of this condition.

[Growth stimulus of the paranasal sinuses with tissue expanders]. / Estímulo no crescimento dos seios paranasais com expansores teciduais.

Various congenital craniofacial deformities show hypoplastic paranasal sinus. The Treacher Collins, the Apert and Crouzon Syndromes and the Hemicraniofacial Microsomy, among others, are typical examples of this observation. Stimuli to the growth of the paranasal sinus during the facial growth period could sensibly improve the treatment of deformity, or even avoid later surgeries. Since their introduction in plastic surgery, tissue expanders are progressively acquiring greater importance in many areas of the specialty. This is a safe and simple alternative to solve difficult cases. It has been demonstrated that real tissue growth occurred in all layers of cutaneous tissues subjected to expansion, including the induction of mitoses. Recent works showed that microorbits could be corrected through the introduction of expanders in their orbits. The authors proposed that to stimulate the growth of paranasal sinus, tissue expanders should be introduced bilaterally in the maxillar, frontal, ethmoidal and sphenoidal sinus, which should promote the development of the face. The expansion induced should be controlled and gradual through injections of small amounts of saline in each session. This project includes the cautious design of the size and shape of the expanders as well as the care with adequate draining of the sinusal cavity and the possible mechanical atrophy of the mucosal lining of the sinus.