Breast Implant Capsule: A Murine Model Comparing Capsular Contracture Susceptibility Among Six Breast Implants Available in the Market

BACKGROUND

Breast implant capsule development and behavior are mainly determined by implant surface combined with other external factors such as intraoperative contamination, radiation or concomitant pharmacologic treatment. Thus, there are several diseases: capsular contracture, breast implant illness or Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL), that have been correlated with the specific type of implant placed. This is the first study to compare all major implant and texture models available in the market on the development and behave of the capsules. Through a histopathological analysis, we compared the behavior of different implant surfaces and how different cellular and histological properties give rise to different susceptibilities to develop capsular contracture among these devices.

METHODS

A total of 48 Wistar female rats were used to implant 6 different types of breast implants. Mentor®, McGhan®, Polytech polyurethane®, Xtralane®, Motiva® and Natrelle Smooth® implants were employed; 20 rats received Motiva®, Xtralane® and Polytech polyurethane®, and 28 rats received Mentor®, McGhan® and Natrelle Smooth® implants. The capsules were removed five weeks after the implants placement. Further histological analysis compared capsule composition, collagen density and cellularity.

RESULTS

High texturization implants showed the highest levels of collagen and cellularity along the capsule. However, polyurethane implants capsules behaved differently regarding capsule composition, with the thickest capsules but fewer collagen and myofibroblasts than expected, despite being generally considered as a macrotexturized implant. Nanotextured implants and microtextured implants histological findings showed similar characteristics and less susceptibility to develop a capsular contracture compared with smooth implants.

CONCLUSIONS

This study shows the relevance of the breast implant surface on the definitive capsules' development, since this is one of the most differentiated factors that determine the incidence of capsular contracture and probably other diseases like BIA-ALCL. A correlation of these findings with clinical cases will help to unify implant classification criteria based on their shell and their estimated incidence of capsule-associated pathologies. Up to this point, the establishment of additional groups is recommended as nanotexturized implants seem to behave differently to pure smooth surfaces and polyurethane implants present diverse features from macro- or microtextured implants.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Measuring Patient-Reported Outcomes After Facial Paralysis Reconstruction Surgery Using the FACE-Q

Background: Patients affected by facial paralysis often experience significant psychosocial impairment, it is, therefore, essential to incorporate their perspective when assessing surgical outcomes. Objective: To study the effect of various patient- and treatment-specific factors on patient satisfaction after facial paralysis reconstruction as measured by FACE-Q. Methods: Seventy-two patients who underwent facial paralysis procedures by our senior author from 2000 to 2020 received the FACE-Q by email. Patient characteristics, duration of paralysis before surgery, type of surgery, complications, and secondary procedures were recorded. Results: Forty-one patients successfully completed the questionnaire. We found that men were significantly more satisfied with the decision to undergo surgery, older patients had significantly lower satisfaction scores with their face and psychosocial well-being, and uninsured patients had higher satisfaction scores with their face and their social and psychosocial well-being, whereas those items were significantly lower in patients with a long-standing facial paralysis. No differences were found between static and dynamic techniques, the presence of complications or the need for secondary procedures. Conclusions: This study found that decreased patient satisfaction was associated with older age, female sex, insured patients, and longer duration of the paralysis before treatment for facial paralysis reconstruction.

Botulinum toxin type A infiltration in spasticity and cervical dystonia. Muscle morphology: an overlooked factor

INTRODUCTION

Botulinum toxin type A is used to treat spasticity and dystonia. However, its relationship with muscle morphology has not been studied. The action mechanism of botulinum toxin is based on the inhibition of acetylcholine release. Therefore, larger doses of toxin would be needed to treat larger muscles. This study aims to establish whether there is a discrepancy between muscle morphology and the botulinum toxin doses administered.

METHODS

We dissected, and subsequently measured and weighed, muscles from the upper and lower limbs and the head of a fresh cadaver. We consulted the summary of product characteristics for botulinum toxin type A to establish the recommended doses for each muscle and calculated the number of units infiltrated per gramme of muscle.

RESULTS

Different muscles present considerable morphological variability, and the doses of botulinum toxin administered to each muscle are very similar. We observed great variability in the amount of botulinum toxin administered per gramme of muscle, ranging from 0.3 U/g in the biceps femoris to 14.6 U/g in the scalene muscles. The mean dose was 2.55 U/g. The doses administered for nearly all lower limb muscles were below this value.

CONCLUSIONS

There are significant differences in morphology between the muscles of the lower limbs, upper limbs, and head, but similar doses of botulinum toxin are administered to each muscle. These differences result in great variability in the number of units of botulinum toxin administered per gramme of muscle.

An Experimental Murine Model to Assess Biofilm Persistence on Commercial Breast Implant Surfaces

Capsular contracture is the most frequently associated complication following breast implant placement. Biofilm formation on the surface of such implants could significantly influence the pathogenesis of this complication. The objective of this study was to design an experimental model of breast implant infection that allowed us to compare the in vivo S. epidermidis ability to form and perpetuate biofilms on commonly used types of breast implants (i.e., macrotexturized, microtexturized, and smooth). A biofilm forming S. epidermidis strain (ATCC 35984) was used for all experiments. Three different implant surface types were tested: McGhan BIOCELL® (i.e., macrotexturized); Mentor Siltex® (i.e., microtexturized); and Allergan Natrelle Smooth® (i.e., smooth). Two different infection scenarios were simulated. The ability to form biofilm on capsules and implants over time was evaluated by quantitative post-sonication culture of implants and capsules biopsies. This experimental model allows the generation of a subclinical staphylococcal infection associated with a breast implant placed in the subcutaneous tissue of Wistar rats. The probability of generating an infection was different according to the type of implant studied and to the time from implantation to implant removal. Infection was achieved in 88.9% of macrotextured implants (i.e., McGhan), 37.0% of microtexturized implants (i.e., Mentor), and 18.5% of smooth implants (i.e., Allergan Smooth) in the short-term (p < 0.001). Infection was achieved in 47.2% of macrotextured implants, 2.8% of microtexturized implants, and 2.8% of smooth implants (i.e., Allergan Smooth) in the long-term (p < 0.001). There was a clear positive correlation between biofilm formation on any type of implant and capsule colonization/infection. Uniformly, the capsules formed around the macro- or microtexturized implants were consistently macroscopically thicker than those formed around the smooth implants regardless of the time at which they were removed (i.e., 1−2 weeks or 3−5 weeks). We have shown that there is a difference in the ability of S epidermidis to develop in vivo biofilms on macrotextured, microtextured, and smooth implants. Smooth implants clearly thwart bacterial adherence and, consequently, biofilm formation and persistence are hindered.

Maximizing the Smile Symmetry in Facial Paralysis Reconstruction: An Algorithm Based on Twenty Years' Experience

Over the last two decades, the senior author (B.H.) has had an extensive experience with facial paralysis reconstruction. During this period, the techniques have evolved substantially based on the experience and after observing and analyzing the surgical outcomes. The purpose of this article is to relay the lessons learned from the 20 years' experience and suggest an algorithm. In this retrospective study, we have included 343 cases of facial paralysis cases. Complete facial paralysis cases were 285 and 58 were incomplete facial paralyses, both requiring surgical procedures. Complete facial paralyses were divided in to short term (n = 83) and long term (n = 202). In total, 58% of the patients were women and 42% were men. The age range was 6 to 82 years. The techniques employed were direct suture, nerve grafts, cross-facial nerve grafts (CFNGs), masseteric-to-facial nerve transference, hypoglossal-to-facial nerve transference, free muscle transplants, and lengthening temporal myoplasty to achieve the best symmetry after reanimation of unilateral, bilateral, complete, and incomplete facial paralysis. The type of paralysis, objective measurements, the personal patient's smile, and the gender are key concepts to be considered before scheduling a dynamic facial paralysis reconstruction. For unilateral facial paralysis, the time of onset, the type of paralysis, the patient's comorbidities, and the healthy side status are some of the determining factors when selecting the correct technique. The preferred techniques for unilateral facial paralysis are direct repair, CFNG, masseteric-to-facial transposition, and free gracilis transfer. For incomplete facial paralysis, the masseteric-to-facial nerve transference is preferred. In bilateral facial paralysis, bilateral free gracilis transfer is performed in two stages using the nerve of the masseter muscle as the source of innervation. The authors provide an algorithm which simplifies facial paralysis reconstruction to achieve the greatest facial symmetry while thinking about the potential comorbidities and developing spontaneity smile according to the gender of the patient.

Tips and Pearls for Recovering Symmetry after Facial Palsy Using a Tendon Sling: Our 20-Year Experience

Background: In facial palsy reconstruction, static techniques with the use of slings can improve the appearance and functionality of the paralyzed face and may be used in patients who cannot undergo complex surgeries or as an ancillary procedure to a dynamic reconstruction. The objective of this study was to assess the improvement in facial symmetry and quality of life among older patients with flaccid facial palsy with the use of a plantaris tendon sling. Methods: A total of 46 patients who had undergone a static reconstruction with the plantaris tendon sling were studied. The surgical technique is detailed emphasizing the tips and pearls. Results: The displacement of the oral commissure was assessed with the FACIAL CLIMA demonstrating a mean elevation of 1.5 ± 0.4 cm and an improvement of 97 ± 7% in the recovery of oral commissure symmetry 2 years after the surgery, whereas the Sunnybrook Facial Grading System showed an improvement of symmetry at rest (-15 ± 5) at 2 years. The Facial Disability Score indicated an improvement of the physical disability (+73.5 ± 14) as well as the social impairment (+21 ± 7) at 1 year postoperatively. Patients were followed for a median of 2 years (range 2-6 years). Conclusions: The use of tendon slings for static facial paralysis reconstruction is a reliable technique with no functional sequelae and good long-term results.

The Relationship Between Patients' Personality Traits and Breast Reconstruction Process

BACKGROUND

Breast reconstruction after mastectomy is a part of breast cancer treatment. There is a lack of data regarding the impact of reconstruction over psychological traits and quality of life. The aim of this study is to evaluate personality changes in patients who underwent reconstructive surgery.

METHODS

Thirty-seven women underwent breast reconstruction. These women took the Crown-Crisp Experiential Index before and after the different procedures. The questionnaire analyzes: (a) the satisfaction level with personal relationships before and after surgery, and the level of satisfaction with surgical results and (b) personality index. Comparisons of preoperative and postoperative personality traits were made by using the Crown-Crisp test and analyzed by Chi-square test. Correlations between preoperative concerns and CCEI traits and correlations between physical aspects and Crown-Crisp, both preoperatively and postoperatively, were performed using the Spearman test.

RESULTS

We found statistically significant differences in the following traits: anxiety anticipating possible technique failures (p = 0.01); cancer recurrence (p = 0.04); dissatisfaction with results (p = 0.02); phobic anxiety for possible technique failure (p = 0.03); obsessionality with possible technique failure (p = 0.01); preoccupations around cancer recurrence (p = 0.01) and dissatisfaction with results (p = 0.03); somatic of technique failure (p = 0.05); and finally, depression and hysteria traits in response to surgical procedures except anesthesia.

CONCLUSION

This prospective study suggests that personality traits define perceptions of body image, which has an influence over quality of life and satisfaction with results.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effect of P144® (Anti-TGF-β) in an "In Vivo" Human Hypertrophic Scar Model in Nude Mice

Background

Hypertrophic scars are one of the most important complications in surgery due to their cosmetic and functional impairments. Previous studies in tissue fibrotic disorders have shown promising results by inhibiting the biological activity effect of Transforming Growth Factor-beta 1 (TGF-β1). The aim of the current study was to determine the clinical effect of the inhibition of TGF-β1 signaling in human hypertrophic scars implanted in nude mice by topical application of an inhibitor of TGF-β1 (P144®).

Material and Methods

A total of 30 human hypertrophic scars were implanted in 60 nude mice. The animals were divided in two groups, group A (placebo) and group B (treatment). Group C (basal) was considered as the preimplanted scar samples and they were not implanted in the nude mice. After the shedding period, topical application of a lipogel containing placebo (group A) or P144 (group B) was daily administered during two weeks. The animals were sacrificed upon completion of the study. Total area, thickness and collagen fibers area were measure and compared across all groups. Immunohistochemistry was also performed in order to quantify collagen type I and type III and elastic fiber expressions present in the dermis.

Results

Successful shedding was achieved in 83,3% of the xenografts. The mean time for shedding was 35±5.4 days. Statistically significant differences were found in the total area, collagen fibers area and thickness between the groups. Increased elastic fibers and decreased collagen I were found in the P144-treated group compared to the basal group.

Conclusion

Topical application of an inhibitor of TGF-β1 may promote scar maturation and clinical improvement of hypertrophic scar morphology features in an “in vivo” model in nude mice after two weeks of treatment.

Masseteric nerve for reanimation of the smile in short-term facial paralysis

Our aim was to describe our experience with the masseteric nerve in the reanimation of short term facial paralysis. We present our outcomes using a quantitative measurement system and discuss its advantages and disadvantages. Between 2000 and 2012, 23 patients had their facial paralysis reanimated by masseteric-facial coaptation. All patients are presented with complete unilateral paralysis. Their background, the aetiology of the paralysis, and the surgical details were recorded. A retrospective study of movement analysis was made using an automatic optical system (Facial Clima). Commissural excursion and commissural contraction velocity were also recorded. The mean age at reanimation was 43(8) years. The aetiology of the facial paralysis included acoustic neurinoma, fracture of the skull base, schwannoma of the facial nerve, resection of a cholesteatoma, and varicella zoster infection. The mean time duration of facial paralysis was 16(5) months. Follow-up was more than 2 years in all patients except 1 in whom it was 12 months. The mean duration to recovery of tone (as reported by the patient) was 67(11) days. Postoperative commissural excursion was 8(4)mm for the reanimated side and 8(3)mm for the healthy side (p=0.4). Likewise, commissural contraction velocity was 38(10)mm/s for the reanimated side and 43(12)mm/s for the healthy side (p=0.23). Mean percentage of recovery was 92(5)mm for commissural excursion and 79(15)mm/s for commissural contraction velocity. Masseteric nerve transposition is a reliable and reproducible option for the reanimation of short term facial paralysis with reduced donor site morbidity and good symmetry with the opposite healthy side.

Retrospective study of the functional recovery of men compared with that of women with long-term facial paralysis

Sex is likely to play an important part in reanimation of the face after paralysis, with women being superior in terms of resistance to neural injury and regeneration. Our aim was to evaluate the influence of the sex of the patient on the recovery of facial paralysis after surgical reanimation by comparing the degree of restored movement between men and women with long-standing paralysis that was reanimated by transfer of the hypoglossal nerve or cross-face nerve grafting. Between 1999 and 2010 we operated on 174 patients with facial paralysis. Of these we studied 26 cases (19 women and 7 men) with complete long-standing paralysis reanimated with either cross-face nerve grafting (n=14) or transfer of the hemihypoglossal nerve (n=12). The degree of movement restored was recorded in each case. Statistical analysis showed that in cases with long-standing paralysis women had significantly more movement restored than men for both cross-face nerve grafting (p=0.02) and hypoglossal transposition (p=0.04). We conclude that, after a neural injury, women tend to maintain the viability of the facial musculature longer than men, which suggests that they are more resistant to both denervation and the development of muscular atrophy. Whether this phenomenon can be explained by neural or muscular processes, or both, warrants further studies.

Effect of the inhibitor peptide of the transforming growth factor beta (p144) in a new silicone pericapsular fibrotic model in pigs

BACKGROUND

Capsular contracture is the most common complication associated with silicone prostheses. It may take the form of anything from slight hardening to obvious deformity. The role of transforming growth factor beta (TGF-beta) in the scar physiopathology of any fibrotic process has been demonstrated. The effects of inhibition of TGF-beta have also been demonstrated in experimental models of fibrosis, which opens the way for new therapeutic alternatives in the treatment of capsular contracture. The aim of this study was to evaluate periprosthetic fibrosis with a newly synthesized TGF-beta peptide inhibitor (p144).

METHODS

Three experimental groups were formed: Group I, subcutaneous and submuscular textured silicone prostheses were left untreated; Group 2, the prostheses were left after being immersed in the vehicle; Group 3, the same protocol was followed as in Group 2, but the solution contained the vehicle with the inhibitor peptide of TGF-beta, p144 (15 mg/prosthesis). The animals were sacrificed 24 weeks after implantation, and the capsules were assessed both macroscopically and histologically.

RESULTS

The results obtained showed that the inhibition of capsular thickness and soluble collagen content in pericapsular fibrosis did not significantly decrease in the group of animals treated with the TGF-beta inhibitor peptide in comparison with control cases.

CONCLUSIONS

We detected no statistically significant reduction in fibrosis in the periprosthetic capsule after treating the implants with the inhibitor peptide p144, but we feel that the influence of trauma around the prosthesis is critical in impeding the antifibrotic activity of the inhibitor peptide.

Evaluation of freezing in arterial microsurgical anastomosis

In this work, the authors discuss the effect of freezing on vascular anastomosis performed in the femoral arteries of the rat. For this purpose, they utilize dimethyl propane ether (-60 degrees C). Two experiments were performed independently from each other. On the right side, they froze the artery before cutting and anastomosing it. On the left side, the artery was first transected and then frozen before anastomosis was performed. Patency was studied at 7 days. Changes in diameter of the vascular lumen were measured both in the experimental as well in the control group. Permeability of the arteries frozen before being cut was greater than in those in which freezing was performed subsequently. On the other hand, the authors found some cases of thrombosed vessels, which have not been previously described in the literature. They also noticed proximal and distal vasospasm when cool was applied locally. They conclude that freezing of microarteries before cutting them produces vasodilatation with a low incidence of thrombotic phenomena. However, the presence of a significant proximal and distal vasospasm leads them to believe that further studies are necessary before this technique is applied in the clinical setting.

Automatic three-dimensional quantitative analysis for evaluation of facial movement

The aim of this study is to present a new 3D capture system of facial movements called FACIAL CLIMA. It is an automatic optical motion system that involves placing special reflecting dots on the subject's face and video recording with three infrared-light cameras the subject performing several face movements such as smile, mouth puckering, eye closure and forehead elevation. Images from the cameras are automatically processed with a software program that generates customised information such as 3D data on velocities and areas. The study has been performed in 20 healthy volunteers. The accuracy of the measurement process and the intrarater and interrater reliabilities have been evaluated. Comparison of a known distance and angle with those obtained by FACIAL CLIMA shows that this system is accurate to within 0.13 mm and 0.41 degrees . In conclusion, the accuracy of the FACIAL CLIMA system for evaluation of facial movements is demonstrated and also the high intrarater and interrater reliability. It has advantages with respect to other systems that have been developed for evaluation of facial movements, such as short calibration time, short measuring time, easiness to use and it provides not only distances but also velocities and areas. Thus the FACIAL CLIMA system could be considered as an adequate tool to assess the outcome of facial paralysis reanimation surgery. Thus, patients with facial paralysis could be compared between surgical centres such that effectiveness of facial reanimation operations could be evaluated.

Peripheral nerve regeneration through allografts compared with autografts in FK506-treated monkeys

Object

The clinical use of nerve allografts combined with immunosuppressant therapy has become a genuine possibility that could supersede the classic use of autografts. However, contradictory data have been reported on whether immunosuppressant therapy should be temporarily administered. The purpose of this study was to compare the nerve regeneration obtained using ulnar nerve allografts in nonhuman primates temporarily treated with FK506 (tacrolimus) with that obtained using nerve autografts.

Methods

Four-centimeter nerve autografts or allografts were placed in the distal ulnar motor nerve of eight monkeys. The FK506 was temporarily administered to the animals of the allograft group for 2 months. At periods of 3, 5, and 8 months postsurgery, quantitative electrophysiological recordings were obtained to estimate muscle response. A quantitative analysis of ulnar motor neurons in the spinal cord was performed and axons were counted stereologically.

No statistically significant differences were found in the neuronal and axonal counts between autograft and allograft groups at 8 months. The electrophysiological studies showed no differences relative to the amplitude, but the autograft group presented with a greater nerve conduction velocity (NCV). However, no statistically significant differences were found between the number of neurons and distal axonal counts in the two groups.

Conclusions

Nerve regeneration through cold-preserved allografts in a primate model temporarily treated with FK506 was similar to that obtained using nerve autografts, in terms of neuronal and axonal counts. Nevertheless, temporary immunosuppression produced lower NCV when allografts were used, with less maturation of the myelinated fibers, which indicated that a partial rejection had taken place.

Neuronal Quantification in Cold-Preserved Nerve Allografts and Treatment with FK-506 Through Osmotic Pumps Compared to Nerve Autografts

Nerve regeneration across nerve autografts was compared to cold-preserved nerve allografts and treatment with FK-506. The tibial branch of the rat sciatic nerve was transected and immediately repaired with nerve autografts and allografts. FK-506 was administered for 4 weeks through osmotic pumps to different groups of both auto- and allograft cases. The nerves of two allografted groups were preserved with University of Wisconsin Cold Storage Solution (UWCSS) for 3 weeks. Quantification of retrograde-labelled motoneurons and axonal counts was performed. Nerve regeneration through nerve allografts treated with FK-506 or UWCSS was similar to the regeneration obtained when non-treated nerve autografts were used. However, there was no additive effect of the two treatments, and neither FK-506 nor UWCSS improved the number of gamma motoneurons. Both UWCSS and FK-506 administration with osmotic pumps was effective in improving nerve regeneration in allografts, achieving a level comparable to that obtained in non-grafted control cases.

Nerve Regeneration through Nerve Autografts and Cold Preserved Allografts using Tacrolimus (FK506) in a Facial Paralysis Model: A Topographical and Neurophysiological Study in Monkeys

OBJECTIVE

Nerve regeneration through cold preserved nerve allografts is demonstrated, and treatment of nerve allografts with FK506 induces better regeneration than other immunosuppressants. We study nerve regeneration through cold preserved nerve allografts temporarily treated with FK506 and compare it with the regeneration obtained using classic nerve autografts in a facial paralysis model in monkeys.

METHODS

A trunk of the facial nerve on both sides was transected in eight monkeys and immediately repaired with a 3 to 4 cm nerve autograft or allograft. FK506 was administered to the animals of the allograft group for 2 months, and nerve allografts were cold preserved for 3 weeks. At periods of 3, 5, and 8 months after surgery, quantitative electrophysiological assessment and video recordings were performed. At the end of the study, quantitative analysis of neurons in the facial nucleus was carried out, and axons were stereologically counted.

RESULTS

After the regenerative period, neuronal density was higher in the autograft group. However, distal axonal counts were similar in both groups. Serial electrophysiological recordings and histology of nerve allografts showed that the grafts were partially rejected after cessation of the immunosuppressant.

CONCLUSION

The regeneration through nerve allografts temporarily treated with FK506 does not achieve the electrophysiological results and neuronal counts achieved with nerve autografts, but axonal collateralization in the allografts induces a similar activation of mimic muscles.

Use of the Transforming Growth Factor-??1 Inhibitor Peptide in Periprosthetic Capsular Fibrosis: Experimental Model with Tetraglycerol Dipalmitate

BACKGROUND

Capsular contracture is the most common specific complication associated with silicone prostheses. It is thought to be caused by the gradual retraction of the fibrous scar tissue that forms around the prosthesis. Molecular biology has made it possible to determine the role of transforming growth factor beta (TGF-beta) in the scar physiopathology of any fibrotic process, including periprosthetic capsular fibrosis. The effects on the inhibition of TGF-beta have also been demonstrated in experimental models of scar formation and fibrosis, which opens the way for new therapeutic alternatives in the treatment of capsular contracture.

METHODS

Three experimental groups of 10 rats each were formed to evaluate periprosthetic fibrosis after its modulation with a newly synthesized TGF-beta1 peptide inhibitor in a tetraglycerol dipalmitate matrix. In the first group, subcutaneously and submuscularly placed, smooth, solid silicone prostheses were left untreated; in the second group, the prostheses were left after being immersed in a solution of tetraglycerol dipalmitate; and in the third group, following the same protocol as in the second group, the solution contained tetra-glycerol dipalmitate mixed with the inhibitor peptide of TGF-beta1. The animals were euthanized 8 weeks after implantation, and the capsules were assessed both macroscopically and histologically.

RESULTS

Inhibition of capsular thickness and cellularity was significantly more effective in the group of animals treated with the inhibitor peptide of TGF-beta1.

CONCLUSIONS

The TGF-beta1 inhibitor peptide applied in a matrix with tetraglycerol dipalmitate is significantly effective in achieving a reduction in periprosthetic fibrosis after placement of silicone implants, either subcutaneously or submuscularly. This result suggests new therapeutic approaches.

[Surgical treatment of haemangiomas]

The therapeutic approach to haemangiomas has changed slightly in recent years, moving from a generally conservative attitude to a more aggressive one in some cases. Chronic unaesthetic alterations that might be caused by haemangiomas, psychosocial traumas that can be caused during childhood, together with a better understanding of the behaviour of this type of lesions and advances in safer and more efficient surgical techniques are the basic factors behind this change of attitude. The present paper concentrates on the surgical treatment of haemangiomas, explaining their indications according to the stage of evolution at which they are found, and the surgical techniques employed to resect the lesion with the least morbidity. Similarly, a detailed treatment is given to those lesions that, because of their specific facial anatomical localization, require a special surgical treatment.

Weight measurement of upper eyelid gold implants for lagophthalmos in facial paralysis

The use of the gold weight is an established procedure in the treatment of lagophthalmos and usually produces successful results. The critical technical issues are the firm suture fixation to the tarsal plate and the high location of the weight on this plate. However, the estimated weight of the implant from the trials on the skin of the upper lid fails to obtain the expected eye closure outcomes after surgical implantation on the tarsal plate. One of the main reasons could be the different curvature on the skin and on the tarsal plate of the upper eyelid. In this study, the angles between the vertical line and the surface of the outer (skin) and inner (tarsal plate) part of the upper eyelid have been analyzed when the eye is opened and closed. The results show that an addition of 0.2 g to the gold weight estimated in the trial is required to achieve a similar closure of the eye by means of the gold implant on the tarsal plate.

[Regeneration and repair of peripheral nerves: clinical implications in facial paralysis surgery]

Peripheral nerve lesions are one of the most frequent causes of chronic incapacity. Upper or lower limb palsies due to brachial or lumbar plexus injuries, facial paralysis and nerve lesions caused by systemic diseases are one of the major goals of plastic and reconstructive surgery. However, the poor results obtained in repaired peripheral nerves during the Second World War lead to a pessimist vision of peripheral nerve repair. Nevertheless, a well understanding of microsurgical principles in reconstruction and molecular biology of nerve regeneration have improved the clinical results. Thus, although the results obtained are quite far from perfect, these procedures give to patients a hope in the recuperation of their lesions and then on function. Technical aspects in nerve repair are well established; the next step is to manipulate the biology. In this article we will comment the biological processes which appear in peripheral nerve regeneration, we will establish the main concepts on peripheral nerve repair applied in facial paralysis cases and, finally, we will proportionate some ideas about how clinical practice could be affected by manipulation of the peripheral nerve biology.

Local administration of neurotrophic growth factor in subcutaneous silicon chambers enhances the regeneration of the sensory component of the rat sciatic nerve

An experimental model for local administration of neurotrophic growth factor (NGF) in peripheral nerve lesions is tested. The model consists of a subcutaneous reservoir connected to the sciatic nerve neurorrhaphy. The right sciatic nerves were exposed, severed, and repaired at a level 1.5 cm proximal to their trifurcation. Then, a dome-shaped silicone reservoir connected to the proximal end of a silicone tube was placed subcutaneously in the dorsum of the experimental animal. The distal end of the connecting tube was located in the nerve neurorrhaphy. Two experimental groups were made: Group A (n = 90) received daily doses of a solution containing NGF-7S during the first 4 weeks after surgery and a single weekly dose thereafter. Within this group, three subgroups of 30 rats each were made: A-4 sacrificed 4 weeks after surgery, A-8 sacrificed after 8 weeks, and A-12 after 12 weeks. Group B (n = 90) received the same vehicle solution without NGF under the same schedule and volume as in Group A. Three subgroups were also made as in Group A depending on the survival period. In order to locate the neurons in the dorsal root ganglia, the retrograde tracer horseradish peroxidase was administered at the proximal stump of the sciatic nerve (tibialis branch), which was severed 1 cm distal to the sciatic trifurcation. In respect of the nonoperated side, the percentage between the number of dorsal root ganglia neurons in the NGF-treated group was significantly higher than in the control group (P < 0.001). These results demonstrate that percutaneous administration of multiple doses of NGF in this model enhances sensory nerve regeneration after sciatic lesions evaluated by horseradish peroxidase labeling of dorsal root ganglia neurons.

Radiotransparency of the triglyceride mammary prosthesis: a quantitative analysis with mastectomy specimens

Breast cancer is the most frequent malignant tumor in women. It is estimated that 10 percent of women will present with a breast cancer during their lives. It is well known that mammography is the best technique for the early diagnosis of nonpalpable tumors, thus improving life expectancy. However, mammary prostheses may hide between 23 and 82 percent of the normal mammary tissue in mammography, and thus may delay the diagnosis of malignant mammary tumors, making prognosis worse. To solve this problem, oil-filled prostheses have been developed. In this study, 14 mastectomy specimens were used. Mammograms of the tissue pieces alone and also mammograms of the tissue pieces covering a 270-cc Trilucent prosthesis were used to verify whether the prosthesis allows observation of malignant signs in mammography. Mammograms were evaluated by an independent experienced radiologist. The following variables were studied: number of mammograms necessary to examine each specimen; kilovoltage and milliamperage necessary for each mammogram; number of microcalcification groups (malignant); number of macroscopic calcifications (benign); and rarefaction areas that were suspected for malignancy. All of these variables were measured for both mammograms for which the mastectomy specimens were covering and those for which the specimens were not covering the prothesis. Finally, the kilovoltage and milliamperage increases necessary to visualize the mammograms with mastectomy specimens covering the prosthesis were determined. Statistical analysis of the results obtained was performed. There were no significant differences in the number of mammograms (p = 0.391), the number of microcalcifications (p = 0.890), the number of macrocalcifications (p = 0.239), and finally in the presence of rarefaction areas (p = 1.000) observed in the mammograms in specimens either covering or not covering the prosthesis. However, there were significant differences (p < 0.001) between the kilovoltage and milliamperage applied to carry out the mammograms of specimens with and without the prosthesis. Thus, Trilucent prostheses allow visualization of the microscopic and macroscopic calcifications as well as rarefaction areas in mammograms. However, these mammograms required a higher kilovoltage and milliamperage compared with specimens not covering the prosthesis. To explore the whole gland, it might be necessary to perform two series of mammograms: one to detect the area shadowed by the prosthesis and one to observe the rest of the peripheral gland.

Regeneration of the motor component of the rat sciatic nerve with local administration of neurotrophic growth factor in silicone chambers

The experimental model reported consists of a subcutaneous reservoir connected to a rat sciatic nerve anastomosis. The right sciatic nerve was exposed, served, and repaired at a level 1.5 cm proximal to its trifurcation. Then, a dome-shaped silicone reservoir, connected to the proximal end of a silicone tube, was placed subcutaneously in the dorsum of the experimental animal. The distal end of the connecting tube was located at the nerve anastomosis. There were two experimental groups: Group A animals (n = 90) received daily doses of a solution containing nerve growth factor (NGF)-7S during the first 4 weeks after surgery and a single weekly dose thereafter. Within this group, there were three subgroups of 30 rats each: A-4 sacrificed at 4 weeks after surgery: A-8 sacrificed at 8 weeks; and A-12 at 12 weeks. Group B animals (n = 90) received the same vehicle solution without NGF at the same schedule and volumes as in Group A. There were also three subgroups as in Group A, depending on the survival period: B-4 (n = 30); B-8 (n = 30); and B-12 (n = 30). In order to localize the motoneurons in the spinal cord, the retrograde tracer, horseradish peroxidase (HRP), was administered at the proximal stump of the sciatic nerve (tibialis branch) that was severed 1 cm distal to the sciatic trifurcation (1.5 cm distal to the nerve anastomosis). The number of spinal neurons in the NGF-treated group was statistically significantly higher than in the control group (p < 0.001). These results demonstrate that percutaneous administration of multiple doses of neurotrophic growth factor in this model enhances motor nerve regeneration after sciatic lesions, evaluated by HRP-labeling of spinal motoneurons.

Evaluation of peripheral nerve regeneration by nerve growth factor locally administered with a novel system

An experimental model is presented for the local administration of neurotrophic substances at the site of peripheral nerve lesion. The model consists of a subcutaneously implanted silicone reservoir and a connecting tube with its distal end facing the severed and repaired nerve. Wistar rats (n = 180) were divided into two groups: a control group (saline-treated) (n = 90) and an NGF-treated group (n = 90). After sciatic nerve axotomy, an epineural repair was performed. NGF or saline were injected daily into the subcutaneous reservoir for the first 4 weeks after axotomy and weekly single dose between the 8th and 12th weeks. Both groups were divided into three subgroups of 30 animals each. The animals were sacrificed at 4, 8 and 12 weeks. Myelinated and non-myelinated axonal and thickness of myelin sheaths were quantified at the tibialis branch 25 mm distal to the nerve repair site. Axonal counts showed statistically significant differences between the treated and control groups at 4, 8 and 12 weeks. Finally, at 4 weeks the myelinated axons in the NGF group had significantly thicker myelin sheaths than in the control group. In comparison with other models of administration of different neurotrophic agents, NGF delivered through this system demonstrates a significant capacity for improving nerve regeneration without the problems inherent in multiple anesthesia, device exchange, or short half-life of the NGF single-dose administration.

Distribution of calbindin D-28k and parvalbumin neurons and fibers in the rat basal ganglia

This review deals with the distribution of immunoreactivity for calbindin D-28k (CB) and parvalbumin (PV) in the different nuclei of the rodent basal ganglia analyzed with the data available after the use of single and double antigen procedures applied to single sections. These findings reveal that CB and PV are distributed according to a highly heterogeneous pattern in the caudate putamen complex (CPu), globus pallidus (GP), entopeduncular nucleus (EP), subthalamic nucleus (STh) and substantia nigra (SN) of the rat. In each basal ganglia structure, the two calcium-binding proteins label different neuronal subsets. Therefore, the use of CB and PV immunohistochemistry may be considered as an excellent tool to define distinct chemoarchitectonic and functional domains within the complex organization of the basal ganglia. Double immunohistochemical methods are also useful to illustrate the relationships between the different chemical subdivisions of the CPu, GP, EP, STh and SN and the chemically characterized connections with each other and with other forebrain and brainstem structures. However, specific rules should be followed when combining single and double immunostaining procedures, and the results of such studies must be evaluated with caution. When they are used properly, these methods can reveal hitherto unknown principles of organization of the basal ganglia and thus shed new light on the anatomical and functional organization of this set of subcortical structures involved in the control of motor behavior.

Parvalbumin and calbindin D-28k in the entopeduncular nucleus, subthalamic nucleus, and substantia nigra of the rat as revealed by double-immunohistochemical methods

The cellular localization of calbindin D-28k (CB) and parvalbumin (PV) was analyzed by means of double-immunohistochemical techniques applied to single sections in the entopeduncular nucleus (EP), the subthalamic nucleus (STh), and the substantia nigra (SN) of the rat. In EP, PV-positive cells abounded centrally, where CB immunostaining was minimal. The medial and ventral sectors of EP were markedly enriched with CB neuropil but devoid of PV-positive cells. CB-positive neurons abounded particularly in the rostral pole of EP. In STh, PV-positive neurons and neuropil were concentrated in the lateral two thirds of this nucleus. Only a few PV-positive cells were detected in sectors of STh devoid of PV-positive neuropil. The STh was completely devoid of CB immunostaining. In the rostral two thirds of SN, PV-positive neurons were largely confined to the lateral half of the pars reticulata (SNR), and occurred more ventrally and medially in the caudal third. Intense CB-immunoreactive neuropil was found in medial and dorsal parts of rostral SNR, and CB-positive cells were observed in the SN pars compacta and the ventral tegmental area. PV and CB cells were also observed in the pars lateralis of SN. The markedly heterogeneous pattern of distribution of PV and CB in EP, STh, and SN suggests that these two calcium-binding proteins may label distinct functional domains in each of these three components of the rat basal ganglia.