Use of dermal regeneration template in contracture release procedures: a multicenter evaluation

Integra dermal regeneration template (Integra Life Sciences, Plainsboro, N.J.) is an effective treatment for full-thickness burns. It can also be useful in contracture release procedures; however, the clinical utility of a dermal regeneration template in contracture release procedures has not been adequately characterized. In this multicenter investigation, the outcomes of release procedures incorporating a dermal regeneration template for 89 consecutive patients, who underwent a total of 127 contracture releases, were retrospectively evaluated. The procedures involved the application of Integra, which includes a temporary silicone epidermal substitute and an artificial dermal layer. After formation of a neodermis, the silicone layer is removed and replaced with an epidermal autograft. Data on patient and contracture site history, treatment methods, physician assessments of range of motion or function, patient satisfaction, recurrence, and adverse events were collected with a standardized questionnaire. Release procedures for the study patients involved the neck, axilla, trunk, elbow, knee, hand, and other anatomical sites. The mean postoperative follow-up period was 11.4 months. At 76 percent of the release sites, range of motion or function was rated as good (significant improvement in range of motion or function) or excellent (maximal range of motion or function possible) by physicians. Responding patients expressed satisfaction with the overall results of treatment at 82 percent of the sites. No recurrence of contracture at 75 percent of the sites was observed during follow-up monitoring. Patient age and prior surgical treatment at the site did not significantly affect the results of treatment. However, outcomes were superior at mature sites, i.e., those for which more than 12 months had elapsed since the original injury. Postoperative complications rarely necessitated regrafting. These results indicate that a dermal regeneration template provides a useful alternative technique for contracture release procedures. The study data indicate that this approach leads to favorable functional outcomes and a high rate of patient satisfaction. This modality also seems to be versatile, because a range of anatomical sites are amenable to treatment with a dermal regeneration template, regardless of prior surgical treatment, and both pediatric and adult patients respond well to this form of therapy. Furthermore, Integra confers functional and cosmetic benefits similar to those of full-thickness grafts but without comparable potential for donor-site morbidity.     

Reconstructive breast surgery: referring physician knowledge and learning needs

Despite the positive impact that reconstructive breast surgery can have on a woman's quality of life, the percentage of eligible candidates that have this procedure remains surprisingly low. The authors hypothesized that this may be attributable to inadequate knowledge, inadequate information, and/or misinformation available to physicians caring for these patients. A needs assessment of primary care physicians, general surgeons, oncologists, and plastic surgeons was conducted to determine referring physicians' current level of knowledge of reconstructive breast surgery and to discover potential learning needs. This comprised a survey, focus groups, and individual interviews. Referring physicians rated their own knowledge of reconstructive breast surgery as low. Plastic surgeons rated their referring physicians' knowledge as even lower. Specific learning needs were identified, as large discrepancies between referring physicians' self-reported knowledge of individual breast reconstruction topics and their own opinion of their relevance were revealed. In addition, despite evidence to the contrary, more than one-third of referring physicians indicated a belief that a breast reconstruction delayed the detection of local cancer recurrence and adversely interfered with adjuvant oncologic therapy. This lack of knowledge and misinformation may be negatively affecting patient referrals to plastic surgeons, as more than one-third of referring physicians and 90 percent of plastic surgeons believed that eligible candidates were not being offered referrals because of inadequate referring physician knowledge of this topic. Furthermore, patients older than 49 years were not being referred despite the fact that plastic surgeons would consider these patients as potential surgical candidates. Referring physician gender affected both referral patterns and perceived importance of reconstructive breast surgery. Finally, personal beliefs and past experiences played a role both in physicians' decisions to refer patients and in patients' decisions to have breast reconstructions. These deficiencies in information, knowledge, and learning needs should be addressed by educational interventions during residency training and through continuing education endeavors.     

Impaired beta-cell regeneration in perinatally malnourished rats: a study with STZ.

We investigated the mechanisms implicated in beta-cell mass reduction observed during late fetal and early postnatal malnutrition in the rat. Beta-cell regeneration, including proliferation and neogenesis, was studied after neonatal beta-cell destruction by streptozotocin (STZ). STZ was injected at birth and maternal food restriction was continued until weaning. Beta-cell mass, proliferation, and islet number were quantified by morphometrical measurements on pancreatic sections in STZ-injected normal (C-STZ) and malnourished (R-STZ) rats, with noninjected C and R rats as controls. At day 4, only 20% of the beta cell-mass remained in C-STZ rats. It regenerated to 50% that of noninjected controls, mainly through active neogenesis, as shown by the entire recovery of islet number/cm(2), and also through moderately increased beta-cell proliferation. In contrast, beta-cell mass from R-STZ animals poorly regenerated, despite a dramatic increase of beta-cell proliferation, because islet number/cm(2) recovered insufficiently. In conclusion, perinatal malnutrition impairs neogenesis and the capacity of beta-cell regeneration by neogenesis but preserves beta-cell proliferation, which remains the elective choice to increase beta-cell mass. These results provide an explanation for the impaired capacity of malnourished animals to adapt their beta-cell mass during aging or pregnancy, which aggravate glucose tolerance.     

Exploring the dermal “template effect” and its structure

Scar formation is the problem for clinic surgery. Recent studies showed that the scar formation was closely related to the dermal defect. Three-dimensional (3-d) structures of dermal tissues act as a template to modulate cell functions that are essential the regeneration of skin structure and function. The dermal tissue’s integrity and continuity is a prerequisite for repair to take place. Loss of the dermal tissue integrity and continuity due to trauma leads to a lack of the template effect, which may be one important mechanism that hinders the recovery of cell function, resulting in scar formation. These studies give us two questions: what is the three-dimensional (3-d) structure of the dermal tissue? How do the tissues form? Up to now, it is well known that the molecular structure of collagen, the micro-structure of microfibril, however, the mesoscopic structure of dermal tissues is still unclear. Our recently rudimentary studies showed the problem might be resolved by phase-contrast micro-tomography with synchrotron radiation, which is likely to open new avenues for further investigations on wound regeneration and skin tissue engineering.     

Liver development and regeneration: from laboratory study to clinical therapy

The liver has an unusual capacity to regenerate after a loss of mass and function caused by surgical resection or toxic liver injury. Over the last 10 years there have been major advances in our understanding of the molecular and cellular mechanisms underlying liver development and regeneration. The numerous factors crucial to these phenomena have been identified mainly by using knockout mice. Forward-genetics studies using zebrafish and medaka have also generated many mutants with liver disorders or defects in liver formation. Our goal is to translate knowledge gained from laboratory work and animal models into novel therapies for human liver diseases. Exciting progress has been achieved using human partial liver transplantation and autologous cell therapy.     

Short-term effect of silicone gel on peripheral nerves: a histologic study.

The effect of silicone gel on the peripheral nerve was studied in Sprague-Dawley rats. Silicone gel was placed either extraneurally (N = 36) adjacent to or injected directly in the sciatic nerve (N = 20). Nerve histology was studied every 2 weeks over a 20-week period. Extraneural silicone gel elicited an intense inflammatory response characterized initially by predominantly histiocytes with a few eosinophils, lymphocytes, and foreign-body giant cells. The cellular response peaked at 4 weeks, after which time collagen deposition increased and the thickness of the cellular infiltrate surrounding the gel decreased. The gel was temporarily contained by the inflammatory response, but throughout the time course of the study, gel migration and breakup into smaller droplets occurred. Each droplet appeared to initiate the inflammation-fibrosis cycle anew. Perineural fibrosis was marked by 20 weeks, but there was no penetration of the epineurium by the gel. Intraneurally injected silicone gel also caused a delayed, but similar inflammatory response, eventually followed by fibrosis surrounding the gel. Intraneural gel tended to remain in larger droplets and did not migrate over the duration of this study. No direct evidence of gel toxicity to peripheral nerves was observed in either the extraneural or intraneural gel groups despite the initial intense inflammatory response and subsequent fibrosis.     

Reconstructive surgery for giant penoscrotal elephantiasis: about one case

Elephantiasis of the external genitalia is characterized by lymphedema and thickening of the subcutaneous tissues. This gives the skin an appearance similar to a pachyderm skin. This pathology is invalidating for the patient. Reconstructive surgery is often the only way to restaure aesthetic and functional aspects of the external genitalia. We aim to report a 52 year man with huge penoscrotal elephantiasis who underwent excision and penoscrotal reconstruction at the department of Urology, Yalgado Ouedraogo Teaching Hospital at Ouagadougou.     

Pulmonary oncocytoma. Report of a case with cytologic, histologic and electron microscopic study

The cytology of a pulmonary oncocytoma diagnosed by bronchial brushings is described along with the light and electron microscopic findings. Ultrastructurally, the tumor cells showed mitochondrial hyperplasia and an absence of neurosecretory granules. The possible histogenesis of pulmonary oncocytomas is discussed.     

The vasculature of the rat penis: a scanning electron microscopic and histologic study.

As a basis for understanding the mechanism of erection in an animal model frequently used in research in reproductive biology, the angioarchitecture of the penis of the rat has been described using scanning electron microscopy. Study of the penile vasculature of the rat indicates that the corpora cavernosa penis and the corpus spongiosum are independent erectile tissues, each with its own arterial and venous vessels. The large vascular spaces and abundant smooth muscle of the penile crura are compatible with its role in regulating blood flow to more distal penile tissues. Helicine arteries of the crura, but not the parent deep penile artery or arteries elsewhere, have muscular cushions in their walls. The venous drainage of the penile crura is via subtunical veins which are thought to be compressed during erection to elevate pressure within the penis. Large, paired cavernous veins drain the shaft of the penis. A unique method for inhibiting blood flow from the penis is indicated by the division of the cavernous veins into smaller channels prior to joining the subtunical venous plexus. Erectile tissue in the bifid origins of the corpus spongiosum has abundant cavernous muscle, while in the remainder of the corpus spongiosum little smooth muscle lines the cavernous spaces. The cavernous spaces on either side of the urethra coalesce to form vessels, each of which communicates with cavernous spaces in the glans. In addition, a bypass of the glans is effected by communication of these vessels directly with the deep dorsal vein. The apparent absence of muscular pads in vessels of the spongiosum, the relative paucity of cavernous smooth muscle, and the ample venous drainage provided by the deep dorsal vein may account for the lack of a venous occlusive mechanism similar to that of the corpora cavernosa penis.     

Choriocapillaris regeneration in the rabbit: a study with vascular casts

Vascular casts were made of the choriocapillaris (CC) of rabbits that received sodium iodate intravenously 6-28 days prior to examination, in order to augment studies of CC regeneration in sectioned material. Regeneration of CC was evident 6 days after administration of iodate where zones of spared CC bordered zones of atrophic CC. Venular as well as capillary sprouts created foci of regenerating CC at this border. These foci to create an extended capillary plexus similar to mature CC. The observations corroborate those obtained in sectioned material as regards the geography of the CC response and the origins of new CC during the sodium iodate retinopathy, and provide new information on the way in which CC regenerates.     

Lizard and newt tail regeneration: a quantitative study

Almost perfect fits of the Gompertz equation to the growth in length of tail regenerates in the lizard, Lacerta lepida, and the newt, Notophthalmus viridescens, were obtained. Comparison of certain parameters of the equation with published mitotic index data suggests that the Gompertz equation characterizes each system at least from the time that significant mitotic activity is first observed histologically. An objective method for comparing the regeneration periods of the two species is described and applied. A unified hypothesis derived from consideration of properties of the Gompertz equation successfully accounts for the following phenomena reported, but previously unexplained, in the literature: (1) proximal amputations result in longer regenerates than do distal amputations; (2) proximal amputations elicit greater absolute rates of elongation (in mm/day) than do distal amputations; (3) the percent replaced of the length removed is rather constant, regardless of the absolute length regenerated; and (4) one of the parameters of the Gompertz equation appears to be lognormally distributed in a regenerating population. (See text for references.) A computerized interactive graphical system for normalizing growth equations of individual regenerates and integrating the mathematical model with potential candidates for biological control factors is briefly described.     

Temporoparietal fascia: an anatomic and histologic reinvestigation with new potential clinical applications

Temporoparietal fascia constitutes a very important structural unit from both an aesthetic and a reconstructive surgical point of view. A histologically supported anatomic study was conducted for the reappraisal of the anatomic relationships and clinical application potentials of the data obtained. Anatomy of the temporoparietal fascia was investigated on 20 sides from 10 cadavers. After dissections, necropsies were obtained to demonstrate histologic features of the temporoparietal fascia. The outer part of the temporoparietal fascia is continuous with the superficial musculoaponeurotic system (SMAS) in the inferior border and with orbicularis oculi and frontalis muscles in the anterior border. Therefore, plication of the temporoparietal fascia can increase tightness of the SMAS, orbicularis oculi, and frontalis muscle in rhytidectomy. The frontal branches of facial nerve were noted to course parallel to the frontal branch of the superficial temporal artery, lying deeper to the temporoparietal fascia within the innominate fascia. In the view of these findings, conventional subfascial dissection, which is performed to protect frontal branches of the facial nerve, is not reasonable during the temporal part of rhytidectomy. Careful subcutaneous dissection just under the hair follicles is more appropriate to avoid nerve injury and also provides excellent exposure of the temporoparietal fascia for plication in rhytidectomy with protection of the auriculotemporal nerve and the superficial temporal vessels. Furthermore, two layered structures of the temporoparietal fascia are very suitable to insert a framework into the temporoparietal fascia for ear reconstruction to eliminate some of the shortcomings of Brent's technique. A thin muscle layer was also noted within the outer part of the temporoparietal fascia below the temporal line; the term "temporoparietal myofascial flap" would, therefore, be more accurate than "temporoparietal fascial flap." Finally, the innominate fascia and the deep temporal fascia can be elevated with the two layers of the temporoparietal myofascial flap to obtain a well-vascularized, four-layered myofascial flap based on the superficial temporal vessels. This multilayered flap can be used to reconstruct all defects when fine, pliable, thin, multilayered flaps are required.