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Biomedical subjects

E Raposio

Publications and source records attributed to E Raposio.

At least 19 recordsLinked to original sources
PubMed1999

Serial scalp reductions: a biomechanical approach.

BACKGROUND: Several technical aspects of scalp-reduction procedures still need to be clearly elucidated: in particular, (a) the quantitative effects provided by different amounts of subgaleal undermining, (b) the immediate gains provided by increasing amount of tension when advancing a scalp flap, and (c) the eventual benefits provided by galeotomies. OBJECTIVE: The aim of the present paper is to report on some biomechanical properties of scalp flaps as related to serial scalp reduction procedures for correction of male pattern baldness. METHODS: Data were collected by stepwise loading of 20 scalp flaps, obtained by a reversed-Y scalp incision, after increasing amounts of undermining, as well as after performing three galeotomies. RESULTS: Increasing amounts of tension (while advancing a scalp flap) affect the compliance of a scalp flap in a non-linear fashion; increasing amounts of undermining permit obtaining significant, but not proportional, gains; performing galeotomies is a useful adjunct to decrease the amount of closing tension when performing scalp-reduction procedures. CONCLUSION: When performing serial scalp reductions, to take into account the biomechanics of scalp flaps may be of some utility in obtaining an optimal result.

Adult↗
PubMed1999

Scalp extension--a quantitative study.

The authors have compared the results of scalp reductions with extenders with their earlier results of scalp reductions without extenders. The extenders seem to prevent "stretch-back" and provide 30 to 86% more effectiveness when a second reduction is performed 4 weeks later.

Alopecia↗
PubMed1999

Effects of cooling micrografts in hair transplantation surgery.

BACKGROUND: When isolating hair grafts in hair transplantation procedures, it is generally recommended to preserve the grafts at a low temperature (1 degrees C- 4 degrees C) in order to enhance the survival rate of the grafted hairs. This study was carried out to test the real benefits provided by cold-storing hair grafts. OBJECTIVE: The aim of this study was to evaluate, in an in vitro model, the effects of cooling micrografts during hair transplantation procedures to experimentally assess the soundness of this approach to enhance the survival and growth rates of hair micrografts. METHODS: A total of 240 anagen hair follicles were obtained from 10 healthy male patients. Follicles were thus randomly assigned to one of the following groups: group A (control; n = 120 follicles), or group B (experimental; n = 120 follicles). Follicles from group A were preserved for 5 hours at room temperature (26 degrees C), and follicles from group B were preserved for 5 hours at 1 degrees C. Immediately after that 5-hour period, follicles from both groups were then cultured for 10 days. The length of each follicle was measured immediately following the 5-hour test period and at the end of the 10-day culture period. RESULTS: No statistically significant differences were found between the survival and growth rates of follicles from the control (survival rate = 87%, mean 10-day growth rate = 2.68 mm) and experimental (survival rate = 88%, mean 10-day growth rate = 2.54 mm) groups. CONCLUSION: Although, at present, it is generally assumed that lowering the metabolism of grafts by reducing their temperature may be of some utility for enhancing their survival rate, our data indicate of that there are no effects when performing hair transplantation surgery.

Adult↗
PubMed1999

Topical application of DMSO as an adjunct to tissue expansion for breast reconstruction.

The aim of this study was to evaluate the effectiveness of topical 60% dimethyl sulphoxide (DMSO) prior to tissue expansion for breast reconstruction in reducing expander pressure and length of treatment. Forty patients undergoing immediate breast reconstruction with tissue expanders following modified radical mastectomy were consecutively divided into two groups of 20 subjects each: group A (control) and group B (experimental). Patients from group A underwent traditional tissue expansion, while, to patients of group B, before each filling session, topical 60% DMSO was applied to the skin overlying the expander by soaking-wet surgical sponges left in place for 30 min. The average inflated volume was 395 cc (range 250-580 cc) in group A, and 410 cc (range 240-620 cc) in group B; no statistically significant difference was found between these values. A statistically significant difference was found between the expansion time of group A (mean 6 sessions; range 4-10 sessions with one filling session per week) and group B (mean 4 sessions; range 2-6 sessions with one filling session per week). A statistically significant difference was also found between the average inflated volume per session of group A (90 cc; range 60-130 cc) and group B (120 cc; range 90-160 cc). According to the data obtained by tonometry, a statistically significant difference was found between the average pre-filling and post-filling pressures of group A (28.4 and 66.5 mmHg, respectively) and group B (22.1 and 64.3 mmHg, respectively). Clinical benefits of pre-filling topical applications of 60% DMSO observed in our trial were an enhancement of the total volume inflatable per session and a significant shortening of the total expansion period.

Administration, Cutaneous↗
PubMed1999

Fetal unilateral cleft lip and palate: detection of enzymic anomalies in the amniotic fluid.

Aims of this study were to evaluate whether it is possible to determine, by means of isoelectric focusing, an enzymic differentiation in human amniotic fluid, and whether the onset of fetal cleft lip and palate is accompanied by a pathologic enzymatic differentiation pattern in amniotic fluid. From January of 1993 to June of 1996, amniotic fluid samples from 315 healthy pregnant women (ages 22 to 43 years, mean 37 years; gestational age 14 to 22 weeks, mean 17 weeks) were examined. The normality of all pregnancies was confirmed at birth. Moreover, amniotic fluid samples were examined from three pregnancies (ages 36, 35, and 30 years; gestational ages 16, 18, 24 weeks) with fetal unilateral cleft lip and palate (confirmed at birth), diagnosed by ultrasound. The authors have tested as "metabolic" markers the enzymes lactate dehydrogenase and creatine phosphokinase. For the concentration rates of both the tested enzymes, a statistically significant difference (p = 0.003) was found between amniotic fluid samples obtained from normal and affected pregnancies. These data, in the authors' opinion, corroborate the hypothesis that a local metabolic impairment is somehow involved in the pathogenesis of cleft lip and palate.

Adult↗
PubMed1999

Ineffectiveness of acute scalp expansion.

The aim of this study was to test the ex vivo biomechanical properties of acutely expanded scalp flaps to quantitatively assess the efficacy of acute scalp expansion. A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (4 x 10 cm), laterally based flap was designed on each side of the scalp, starting from the superior margin of the external auditory canal. One randomly selected flap per scalp underwent acute intermittent expansion (a 3-minute expansion/3-minute rest cycle was performed three times with the maximum expansion achievable); the contralateral flap served as a control. After the expansion process, the acutely expanded flaps were measured to assess whether applied biomechanical stress caused any changes in flap dimensions. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force transducer. The obtained data showed that the biomechanical benefits provided by acute scalp expansion were not statistically different (p < 0.05) from those obtained by simple subgaleal undermining. No change of length nor gain in compliance was observed in the acutely expanded flaps as compared with control scalp flaps. In the authors' opinion, a possible explanation (to be further validated) for the lack of effect of acute scalp expansion might be that the inelastic galea aponeurotica did not allow mechanical creep to exploit the inherent elastic properties of the overlying scalp skin.

Adult↗
PubMed1999

Two modified techniques for flexor tendon repair.

The aim of this article is to present two new techniques for digital flexor tendon repair: a modification to the conventional Kessler technique (wrap core suture) and tendon splints (H-shaped splint). These techniques were aimed at enhancing the biomechanical properties of such repairs as related to resistance to both gap formation and repair failure. Comparing (in an ex vivo study) the tensiometric properties (gap formation and failure strengths) of 24 flexor digitorum profundus tendons repaired with the described techniques (12 repairs per each technique) and the conventional Kessler repair (24 repairs), we found that the former provided significantly stronger repairs than the latter in vitro. A statistically significant difference (p < 0.001) was found between each of the two presented techniques and the Kessler repair. The wrap core suture increased the load at which a visible (1 mm) gap formed by 22.6 percent when compared with the conventional Kessler suture. The mean gap strength of the wrap core repair was 6.5 N, whereas that of the conventional Kessler was 5.3 N. The failure loads (ultimate strength) of the wrap core suture were 33.8 percent higher than those of the conventional Kessler. The mean breaking load of the wrap core repair was 19.4 N, whereas that of the conventional Kessler was 14.5 N. The H-splint repair increased the load at which a visible gap formed and the failure loads (ultimate strength) by 158.5 and 333.1 percent, respectively, when compared with the conventional Kessler suture. The mean gap strength of the H-splint repair was 13.7 N, and its mean breaking load was 62.8 N.

Biomechanical Phenomena↗
PubMed1998

Pharmacological enhancement of cutaneous flap survival with topical dimethyl sulphoxide and hydrogen peroxide.

The present study was designed to investigate, in a rabbit model, the value of topical application of a solution of hydrogen peroxide (H2O2) 8% + dimethyl sulphoxide (DMSO) 50% in order to reduce ischaemic failure in random skin flaps. Two parallel, cephalad-based para-midline random cutaneous flap (10 cm x 2.5 cm) were elevated and resutured in place on the dorsum of 40 New Zealand rabbits. The 80 flaps thus obtained were then randomly divided into one control group and three experimental groups of 20 flaps each. Flaps from the control group (Group A) were topically treated with saline, while flaps from experimental Group B were treated with H2O2 8%, flaps from experimental Group C with DMSO 50%, and flaps from experimental Group D with a solution of 50% DMSO + 8% H2O2. Each solution was topically applied to the flaps, 20 ml three times a day for 7 days, starting in the immediate postoperative period. Transcutaneous oxygen tension (PtcO2) measurements were carried out in all flaps 72 h after flap elevation. The percentage of surviving skin area of each flap was determined by planimetry 7 days after flap elevation. The mean surviving area of the Group A (control) flaps was 71%, the mean surviving area of the Group B (H2O2-treated) flaps was 72%, the mean surviving area of the Group C (DMSO-treated) flaps was 76%, and that of the Group D (DMSO+H2O2-treated) flaps was 92%. While no statistically significant differences were found between the survival rates of both the flaps treated with H2O2 or DMSO alone and that of the control group, the mean surviving rate of the DMSO+H2O2 treated flaps (+20%) was statistically higher than that of the control flaps. Similarly, a statistically significant difference has been found between the mean PtcO2 values of the DMSO+H2O2 flaps and those of the other three groups of flaps.

Animals↗
PubMed1998

Effects of galeotomies on scalp flaps.

The aim of the present study was to evaluate how much a relaxing incision of the galea aponeurotica affects the biomechanical properties of a scalp flap to quantify the surgery-related advantages provided by this procedure. Twenty scalp flaps, created by a reverse-Y incision down to and through the galea aponeurotica together with undermining (in the layer between the galea and the pericranium) to within 1 cm of the external auditory canal were studied. Data were collected by stepwise loading the scalp flaps before and after performing three full-thickness galeotomies lengthwise and parallel to the sagittal scalp incision. The tension/ extension ratio characteristics were computed, and loading curves as well as mean stiffness values were measured. A statistically significant difference (-16.6 g per millimeter) was found between the slope (computed as Young's modulus) of the curves obtained before and after performing the galeotomies. This value corresponded to a mean 40% reduction of the closing tension attained with each galeotomy. In the closing-tension interval 500 g to 1,500 g, the mean gain of length of the flap per galeotomy was 1.67 mm. These data confirm the usefulness of galeotomies for lengthening the scalp flaps and for diminishing the tension on wound margins when closing scalp defects.

Adult↗
PubMed1998

Undermining of the scalp: quantitative effects.

The aim of the present study was to evaluate to what extent undermining affects the closing-tension of scalp defects to quantify the surgery-related benefits provided by this procedure. Data were collected by stepwise loading in 10 patients, 20 scalp flaps (obtained by a reversed Y scalp incision), and three different degrees of subgaleal undermining (1, 5, and 15 cm). The obtained data confirmed the value of undermining to diminish the tension on wound margins when closing a scalp defect. There was a progressive decrease in tension required to advance the wound edge when the amount of undermining was sequentially increased. Most of this reduction occurred with the 5-cm undermining, although statistically the 15-cm undermining also resulted in a significant decrease in the tension required to close the defect. Mean 83.3- and 92.2-percent reductions of the closing tension were obtained with 5 cm and 15 cm of undermining, respectively, compared with that achieved by the 1-cm undermining with the same width of defect.

Adult↗
PubMed1998

Follicular bisection in hair transplantation surgery: an in vitro model.

The aim of this study was to evaluate, in an in vitro model, the survival and growth rates of transversely sectioned human hair follicles to assess experimentally the soundness of this approach as a future possible method for "duplicating" available donor hair grafts in hair transplantation procedures. A total of 300 human anagen hair follicles was obtained from 10 healthy male patients. Follicles were thus randomly assigned to one of the following groups: group A (control; n = 100 follicles), cultured intact as dissected, and group B (experimental; n = 200 follicles), transversely transected, parallel to the epidermal surface and immediately below the bulge area, to obtain 200 lower-half follicles and 200 upper-half follicles. Isolated hair follicles from both groups were maintained in culture for 10 days. The length of each follicle was measured immediately following isolation and at the end of the 10-day culture period. No statistically significant differences were found between the growth rate of intact follicles (mean 10-day growth rate = 2.71 mm) and of lower-half follicles (mean 10-day growth-rate = 2.64 mm), whereas a statistically significant difference was found between the growth rate of follicles from the two above-mentioned groups and the growth rate of the "upper-half" follicles (mean 10-day growth rate = 1.07 mm). Histologic analysis demonstrated that both intact and lower-half follicles maintained a normal histologic appearance, whereas in upper-half follicle sections we invariably detected a region of intense cell proliferation, reminiscent of a regenerated follicular papilla, surrounding the lowermost part of the follicle. In our opinion, the reported in vitro survival rate of transected human hair follicles might represent an interesting starting point in striving to augment the number of donor hairs available during a hair transplantation procedure.

Adult↗
PubMed1998

Mitochondrial activity of orbicularis oris muscle in unilateral cleft lip patients.

To better evaluate the role of a possible mitochondrial alteration in the pathogenesis of cleft lip, we obtained and examined 38 orbicularis oris muscle specimens taken from the cleft margin of both cleft and noncleft sides of 10 unilateral cleft lip infants at the time of primary closure. Part of each sample was frozen in liquid nitrogen/cooled isopentane, while the remainder was fixed in 2.5% glutaraldehyde, postfixed in osmium tetroxide, and embedded in Araldyte resin. Ten-micrometer-thick sections were obtained from the frozen samples and stained for histologic (Gomori trichrome) and histochemical (adenosine triphosphatase, nicotinamide adenine dinucleotide-tetrazolium reductase, cytochrome c-oxidase, succinate dehydrogenase) techniques. Ultra-thin sections (70 to 100 nm) of the resin-embedded specimens were stained with uranyl acetate and lead cytrate and were examined with a Zeiss 109 transmission electron microscope operating at 80 kV. Muscular fiber-type ratio was found to be 19.2 percent type 1 and 80.8 percent type 2 fibers on the cleft side and 26.3 percent type 1 and 73.7 percent type 2 fibers on the noncleft side. We detected aspecific structural alterations, such as variations in the fiber size without fiber group atrophy or fiber-type grouping with the ATPase reaction, in all biopsies. Although Gomori trichrome revealed a dark staining and red granularity of the fibers, suggesting an increase in mitochondria activity, no ragged-red fibers or cytochrome c-oxidase-negative/succinate dehydrogenase-positive fibers were found. At the ultrastructural level, the mitochondrial morphology was always preserved, without inclusions or variations in size and/or shape. On the other hand, we invariably noticed an increase of the number of mitochondria, associated with abnormal glycogen deposits, in some areas of every specimen. Both of these two latter findings were regularly localized at the periphery of the sarcolemma, resembling the so-called lobulated fibers, an aspecific sign of muscular flogosis. Our findings, although excluding an inherent metabolic myopathy of orbicularis oris muscle in unilateral cleft lip patients, evinced both an increased oxidative metabolism and a generic inflammatory condition of that muscle, the nature of which must still be defined.

Adenosine Triphosphatases↗
PubMed1998

Endoscopic transthoracic dorsal sympathectomy for the treatment of upper extremity hyperhidrosis: a new minimally invasive approach.

Palmar and axillary hyperhidrosis are best treated surgically by endoscopic transthoracic upper dorsal sympathectomy. At present, this methodology relies on (at least) double trocar insertion (per side), carbon dioxide insufflation, or both. We present a new minimally invasive endoscopic transthoracic technique, performed by a single-entry specifically modified thoracoscope and without the need for carbon dioxide insufflation, with the aim to reduce the drawbacks associated with the above-mentioned, currently adopted endoscopic technique. In our opinion, this "single-entry" technique, compared with the other reported approaches, should theoretically minimize any damage to the intercostal neurovascular bundle, while avoiding the complications related to carbon dioxide insufflation.

Adolescent↗
PubMed1998

Anchoring galeal flaps for scalp reduction procedures.

This article describes an operative technique, based on the use of three anchoring galeal flaps, aimed at reducing the percentage of "stretch-back" that occurs after performing scalp reduction procedures. In 12 male patients undergoing a midline scalp reduction procedure, three rectangular (2 x 3 cm) galeal flaps in direct continuity with the longitudinal margin of the left scalp flap were sutured individually to the galeal undersurface of the right scalp flap to draw the two scalp flaps toward the midline of the scalp and to relieve the wound margins of closing tension. Tattoo marks were placed on the patient's scalp at the level of the vertical lines drawn through the external auditory meatuses (A1-A2) and 6 cm more posterior (B1-B2) to measure the movement and stretching of the scalp. The results were compared with those obtained from a control group of 13 male patients who underwent the same surgical procedure but without the use of the anchoring galeal flaps. Mean stretch-back (as measured 4 weeks postoperatively) at level A1-A2 was 8.3 mm in the control group and 1.6 mm in the experimental group. The mean stretch-back at level B1-B2 was 7.7 mm in the control group and 0.9 mm in the experimental group. A statistically significant difference (p < 0.005) was found between data from the control and experimental groups regarding the above-reported stretch-back values at both levels. The use of the described galeal flaps allowed us to obtain an 80.93-percent and an 88.09-percent stretch-back reduction at levels A1-A2 and B1-B2, respectively, 1 month postoperatively.

Adult↗
PubMed1998

Power boosting the grafts in hair transplantation surgery. Evaluation of a new storage medium.

BACKGROUND: When performing hair transplantation procedures, it is of the foremost importance to try to obtain the maximum survival rate possible of transplanted micrografts. OBJECTIVE: Aim of this study was to evaluate, in an in vitro model, the effects of preserving micrografts, for five hours, in an enriched storage medium in order to enhance the survival rate of hair micrografts. METHODS: A total of 200 human anagen hair follicles was obtained from ten male patients. Follicles were thus randomly assigned to one of the following group: Group A (control; n = 100 follicles), preserved for five hours in saline, and Group B (experimental; n = 100 follicles), preserved for five hours in a storage medium, containing adenosine triphosphate-magnesium chloride and deferoxamine mesylate. Isolated hair follicles from both Groups were then cultured for 10 days. RESULTS: A statistically significant difference was found between the survival rate of experimental (98%) and control follicles (87%). CONCLUSION: In our opinion, a "metabolic preconditioning" of micrografts by means of storing them for 5 hours in the described medium may be of some utility in augmenting the survival rate of hair grafts when performing hair transplantation surgery.

Adenosine Triphosphate↗
PubMed1997

Recent results in color compositing of three-parameter magnetic resonance scans as a preoperative aid to the management of upper limb sarcomas.

We report on improved image quality and some recent clinical results with volume-rendered, color composite, multiparameter, magnetic resonance (MR) datasets and their color histograms. In a previous article we demonstrated the major components of an interactive visualization environment for multiparameter T1-, T2-, PD-weighted MR volume datasets. These are compositing of the three parametric volumes, color volume rendering of the resulting composite, interactive segmentation of the tissues based on color cluster statistics derived from display of the three-dimensional (3D) histogram, and head-tracking stereo display. We herein review the system design and describe improvements to the quality of the color volume rendering, in the display of the 3D color histogram data, and in the specification of the volume renderer's opacity function. Finally, we report on some recent clinical results using our system.

Arm↗