Pierluigi Santi

Postquadrantectomy breast deformities: classification and techniques of surgical correction.

The deformity which is encountered following quadrantectomy (or similar procedures such as segmentectomy or partial mastectomy) and radiation therapy is difficult to evaluate objectively, and subjective assessment of the cosmetic outcome is extremely variable. In a group of 54 patients who underwent the procedure between 1979 and 1983, the types of cosmetic changes were evaluated and classified according to morphologic criteria. Four types of deformities and their related etiopathologic factors were identified. Type I is characterized by malposition and distortion of the nipple-areola complex and is mainly due to postoperative fibrosis and scar contracture. In type II deformity, localized tissue insufficiency is observed, which may be due to skin deficiency (type IIa), subcutaneous tissue deficiency (type IIb), or both (type IIab). Type III deformity is characterized by breast retraction and shrinkage and is mainly due to the effects of radiotherapy on residual breast parenchyma. In type IV deformity, severe radiation-induced damage to the skin, nipple-areola complex, and subcutaneous and glandular tissues is present. Surgical correction of each type of deformity is discussed, and examples are reported.

Prefabricated engineered bone flaps: An experimental model of tissue reconstruction in plastic surgery

&NA; In light of the recently described experimental technique of in vivo bone reconstitution with biotechnologic methods (from bone marrow stromal cells) and the prefabrication flap procedures, the possibility to obtain autologous bone growth in a myocutaneous flap, thus creating a composite osteomyocutaneous preformed flap, is postulated. Human bone marrow stromal cells were delivered into the latissimus dorsi of athymic mice by a porous hydroxyapatite ceramic model. Eight weeks after the implantation, histologic examination revealed the presence of spongious bone tissue. A simple myocutaneous flap was thus transformed into a composite osteomyocutaneous flap. This flap is called the biotechnologic prefabricated flap, because it was the result of ex vivo expanded osteogenic precursor cells and in vivo bone tissue neoformation. The shape of the bone flap was exactly the same as the shape of the ceramic model used. A possible clinical application may be the correction of skeletal defects. The advantages of this procedure are simple surgical execution, the possibility of preshaping the graft to the exact characteristics of the defect, and the availability of autogenous donor tissue without donor site morbidity.

Long-term evaluation of the abdominal wall competence after total and selective harvesting of the rectus abdominis muscle.

Fifty patients who underwent unilateral breast reconstruction by transverse rectus abdominis musculocutaneous flap transposition between January 1987 and December 1989 are the object of this study. Every patient underwent selective harvesting of the medial portion of the muscle, whereas the lateral strip was left in place and studied intraoperatively by selective stimulation of the ninth intercostal motor nerve before closure of the fascial defect. Two separate ecographic scans of the abdominal wall were performed respectively 7 days and 6 months postoperatively, to evaluate the diameters of the residual portion of the rectus muscle and its long-term evolution. Our results show that in a considerable number of patients, the lateral strip of rectus was denervated at surgery. Long-term ecographic scans demonstrate, however, that in spite of this finding, the residual muscle usually maintains its diameters, thus significantly contributing to the competence of the abdominal wall, at least from the static point of view.

A Comparative Study of Proliferation and Hepatic Differentiation of Human Adipose-Derived Stem Cells

Human adipose-derived stem cells possess a lot of stem cell characteristics, so they may be considered a source of stem cell population. On the basis of that, we have investigated the hepatic potential of adipose-derived stem cells, obtained from liposuction, following two differentiation protocols. In the first procedure, medium was supplemented with epidermal growth factor (EGF), basic fibroblast growth factor, hepatocyte growth factor (HGF) and nicotinamide; the second involved the addition of factors such as dexametasone, EGF, insulin-transferrin-sodium selenite, HGF, dimethyl sulfoxide and oncostatin. In parallel, we carried out our study in the Hep G2 cell line, as human hepatic differentiated in vitro model. Immunocytochemical analysis and RT-PCR were performed using hepatic markers to evaluate cell differentiation. DNA content, MTT test and carboxyl fluorescein succinimidyl ester staining were carried out to evaluate cell proliferation. We reported the evidence of basal hepatic marker in undifferentiated adipose-derived stem cells, which confirmed their multipotency. A strong expression of albumin and α-fetoprotein was observed in hepatic-induced adipose-derived stem cells following both differentiation procedures. Morphological aspects of the two types of hepatic adipose-derived stem cells were alike. Proliferation index suggested that the first differentiation procedure promoted better growth than the second. These preliminary findings suggest adipose-derived stem cells may be induced into hepatic lineage, and the most significant difference between the two standard differentiation procedures concerns proliferation rate. This aspect is to be considered when adipose-derived stem cells are employed in research and clinical studies.

The transverse rectus abdominis musculocutaneous flap for breast reconstruction in obese patients

Transverse rectus abdominis musculocutaneous (TRAM) flap breast reconstruction has often been considered contraindicated in obese women. The morphological characteristics peculiar to this population, however, make obese women ideal candidates for this procedure because the reconstructed breast must often match a large ptotic contralateral breast. About one-third of our postmastectomy patients are corpulent, middle-aged women with “Mediterranean” body structures. Thirty-four obese women underwent TRAM flap breast reconstruction from 1985 to 1988. According to the Body Mass Index, 23 women had type II obesity and 11 had type III obesity. The preoperative and postoperative management and the surgical procedure were adapted to this particular group of women. The complication rate in this series of women was superior to that of a nonobese population; however, no severe complications were observed. The majority of women were extremely satisfied with aesthetic results; the surgeons also judged the final cosmetic outcome to be very favorable and, indeed, superior to that obtainable with simpler methods. Obesity uncomplicated by other risk factors does not represent an absolute contraindication to TRAM flap procedure.

In vitro polydeoxyribonucleotide effects on human pre-adipocytes

Abstract.  Objectives: Adipose tissue is the most abundant and accessible source of adult stem cells. Human processed lipoaspirate contains pre‐adipocytes that possess one of the a characteristic pathways of multipotent adult stem cells and are able to differentiate in vitro into mesenchymal and also neurogenic lineages. Because stem cells have great potential for use in tissue repair and regeneration, it would be significant to be able to obtain large amounts of these cells in vitro. As demonstrated previously, purine nucleosides and nucleotides mixtures can act as mitogens for several cell types. The aim of this study was to evaluate the effects of polydeoxyribonucleotides (PDRN), at appropriate concentrations, on human pre‐adipocytes grown in a controlled medium, also using different passages, so as to investigate the relationship between the effect of this compound and cellular senescence, which is the phenomenon when normal diploid cells lose the ability to divide further. Materials and methods: Human pre‐adipocytes were obtained by liposuction. Cells from different culture passages (P6 and P16) were treated with PDRN at different experimental times. Cell number was evaluated for each sample by direct counting after trypan blue treatment. DNA assay and the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide test were also carried out in all cases. Results and Conclusions: PDRN seemed to promote proliferation of human pre‐adipocytes at both passages, but cell population growth increased in pre‐adipocyte at P16, after 9 days as compared to control. Our data suggest that PDRN could act as a pre‐adipocyte growth stimulator.

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 Youngs 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.

Correction of Type Ii Breast Deformities Following Conservative Cancer Surgery

Breast deformities following conservative cancer surgery are seen with increasing frequency and often represent difficult reconstructive problems. Type II deformities are characterized by localized tissue insufficiency, which can be due to skin insufficiency (type IIa), subcutaneous tissue insufficiency (type IIb), or both (type IIab). Correction of a locally damaged breast is a surgical challenge that can result in a fully restored breast if selection of the surgical procedure is properly carried out. A series of 37 patients who underwent correction of type II deformities from 1980 to 1989 was reviewed. Results obtained with different surgical procedures, including simple submuscular placement of traditional or expandable implants, breast reshaping, transposition of a latissimus dorsi muscle or musculocutaneous flap, TRAM flap, and reverse abdominoplasty, were evaluated. Aesthetic outcome was judged to be good or excellent in 78 percent of patients. Guidelines for selection of the most appropriate surgical procedure according to the defects etiology, morphology, and location and to the breasts size and shape are presented.

Long-lasting complications with the use of polyurethane-covered breast implants

Polyurethane-covered breast implants have been recommended by some authors for aesthetic and reconstructive procedures, since with these implants the incidence of capsular contracture is insignificant and risks of implant displacement or exposure are reduced. Reports on the use of these implants focus merely on aesthetic aspects, and risks associated with disintegration and incorporation of the polyurethane-coating are often overlooked. The authors have observed several complications associated with the use of these prostheses; two cases of long-lasting complication are described, which are ascribed to difficult removal of infected fragments of the coat and to delayed foreign body reaction to polyurethane. The authors believe that the hazards associated with these implants outweigh their advantages for primary use, but suggest their use for secondary procedures in patients who have had recurrent problems with smooth implants.

Pre-adipocytes commitment to neurogenesis 1: Preliminary localisation of cholinergic molecules

A great effort has recently been made to obtain human stem cells able to differentiate into cholinergic neurons, as a number of diseases are associated to the cholinergic neuron loss, degeneration or incorrect function (Alzheimers disease and motor neuron disease). A stem cell population (i.e. pre‐adipocytes) is present in the adipose stromal compartment. Pre‐adipocytes, like the mesodermic derivative cells, retain high plasticity and potentiality to convert in vitro from one phenotype into many others, and they can be isolated from adult adipose tissue. Pre‐adipocytes committed in vitro to neural differentiation were followed up to the acquisition of neural morphology. Acetylcholinesterase and choline acetyltransferase are expressed from the native cell stage, with different localisations and roles during neural commitment. Western blots show the beginning of a new synthesis of these enzymes at 4 weeks of culture of neurogenic pre‐adipocytes, in parallel with neural morphology. The passage of the choline‐acetyltransferase immunoreactivity from cytoplasmic to membrane localisation shows the possible onset of catalytic activity and the histochemical reaction confirms the activity of acetylcholinesterase. This explains the possibility of obtaining cholinergic‐like phenotype from pre‐adipocytes.