Paulo Kharmandayan

Cranial reconstruction: 3D biomodel and custom-built implant created using additive manufacturing.

Additive manufacturing (AM) technology from engineering has helped to achieve several advances in the medical field, particularly as far as fabrication of implants is concerned. The use of AM has made it possible to carry out surgical planning and simulation using a three-dimensional physical model which accurately represents the patients anatomy. AM technology enables the production of models and implants directly from a 3D virtual model, facilitating surgical procedures and reducing risks. Furthermore, AM has been used to produce implants designed for individual patients in areas of medicine such as craniomaxillofacial surgery, with optimal size, shape and mechanical properties. This work presents AM technologies which were applied to design and fabricate a biomodel and customized implant for the surgical reconstruction of a large cranial defect. A series of computed tomography data was obtained and software was used to extract the cranial geometry. The protocol presented was used to create an anatomic biomodel of the bone defect for surgical planning and, finally, the design and manufacture of the patient-specific implant.

Useful properties of undifferentiated mesenchymal stromal cells and adipose tissue as the source in liver-regenerative therapy studied in an animal model of severe acute fulminant hepatitis

BACKGROUND AIMS End-stage liver diseases frequently require liver transplantation. Cell therapy could be an alternative. This study aimed to analyze whether undifferentiated mesenchymal stromal cells (U-MSCs) or MSC-derived hepatocyte-like cells (DHLCs) from adipose tissue (AT), umbilical cord blood (UCB) and bone marrow (BM) would better restore damaged liver. METHODS AT was obtained from lipo-aspiration, UCB from an Umbilical Cord Blood Bank and BM from a BM Transplantation Unit. AT (collagenase digestion), UCB and BM (Ficoll gradient) were cultured (Dulbeccos modified Eagles medium, low glucose, FBS) for 3 days. Detached adherent cells, at passage 4, were characterized as MSCs. Genetic stability was investigated by means of telomerase enzyme activity and karyotype. Hepatocyte differentiation protocol was performed with the use of Dulbeccos modified Eagles medium, hepatocyte growth factor, basic fibroblast growth factor and nicotinamide (7 days); maturation medium (oncostatin, dexamethasone, insulin, transferrin and selenium) was added at 36 days. Hepatogenesis analyses were performed by use of morphology and albumin, AF, tyrosine-aminotransferase and glutamine synthetase gene expression and quantitative reverse transcription-polymerase chain reaction on days 9, 18, 25 and 36. Functionality was assessed through glycogen storage detection, indocyanine green absorption and transplantation procedure. U-MSCs and DHLCs were injected 48 h after induced fulminant hepatitis (intraperitoneal injection of carbon tetrachloride) in SCID/BALB-c mice. Histopathologic analyses were performed on days 7 and 15. Human origin included albumin and CK19 human markers. RESULTS All MSCs differentiated into functional hepatocyte-like cells, stored glycogen and absorbed indocyanine green. AT-MSC DHLC gene expression was more consistent with a normal hepatogenic-differentiation profile. UCB-MSCs expanded weakly, impairing their use for the transplantation procedure. AT and BM U-MSCs and DHLCs regenerated liver injury equally. Regenerated hepatocytes exhibited human origin. CONCLUSIONS AT might be the source and U-MSCS the stem cells useful for liver-regenerative therapy.

Occurrence of fat embolism after liposuction surgery with or without lipografting: an experimental study.

Background:Liposuction in plastic surgery consists of the removal of excess fatty tissue in healthy individuals. In recent decades, this procedure has become more common worldwide. Associated with liposuction, lipografting has also been used for improving body contours, and has become known as liposculpture. Liposuction sometimes causes complications, including fat embolism, as described in the medical literature. The present study aims at ascertaining whether there is intravascular mobilization of fat after mechanical liposuction surgery and/or fat graft when carried out using one of the most common specific procedures used for liposuction, the superwet technique. Methods:A total of 30 Wistar rats were included in this study. Before the surgery, the animals were placed in the supine position and anesthetized with thiopental for 50 to 60 minutes, as it is generally performed in clinical practice. The animals were divided in the following 3 groups. Group A, consisting of 10 rats, served as controls, and were only anesthetized. Group B consisted of 10 rats, which underwent only liposuction. Group C also comprised 10 rats, which were liposuctioned and then lipografted in the dorsal region. Blood was collected just before and again, 48 hours after the procedure. After 48 hours, the animals were killed, and the lungs, kidneys, liver, and brain were histologically examined. Results:All the collected samples were analyzed microscopically with 2 different stains, namely, hematoxylin and eosin, and Sudan black. Fat particles were found in the lungs of 3 animals in group B (those that underwent only liposuction) and in 6 animals of group C (liposuction and lipografting). No fat particles were found in any organ of the control group. Conclusions:With this experiment, the authors showed that there is a risk of systemic mobilization of fat after liposuction surgery and that this risk is even higher when fat grafts are also carried out.

Microstructural and Mechanical Characterization of a Custom-Built Implant Manufactured in Titanium Alloy by Direct Metal Laser Sintering

Custom-built implants manufacture has always presented difficulties which result in high cost and complex fabrication, mainly due to patients’ anatomical differences. The solution has been to produce prostheses with different sizes and use the one that best suits each patient. Additive manufacturing technology, incorporated into the medical field in the late 80s, has made it possible to obtain solid biomodels facilitating surgical procedures and reducing risks. Furthermore, this technology has been used to produce implants especially designed for a particular patient, with sizes, shapes, and mechanical properties optimized, for different areas of medicine such as craniomaxillofacial surgery. In this work, the microstructural and mechanical properties of Ti6Al4V samples produced by direct metal laser sintering (DMLS) are studied. The microstructural and mechanical characterizations have been made by optical and scanning electron microscopy, X-ray diffraction, and microhardness and tensile tests. Samples produced by DMLS have a microstructure constituted by hexagonal α′ martensite with acicular morphology. An average microhardness of 370 HV was obtained and the tensile tests showed ultimate strength of 1172 MPa, yield strength of 957 MPa, and elongation at rupture of 11%.

Mesenchymal stromal cells from adipose tissue attached to suture material enhance the closure of enterocutaneous fistulas in a rat model

BACKGROUND AIMS Surgical treatment for enterocutaneous fistulas (EF) frequently fails. Cell therapy may represent a new approach to treatment. Mesenchymal stromal cells (MSCs) have high proliferative and differentiation capacity. This study aimed to investigate whether MSCs could adhere to suture filament (SF), promoting better EF healing. METHODS MSCs, 1 × 10(6), from adipose tissue (ATMSCs) were adhered to a Polyvicryl SF by adding a specific fibrin glue formulation. Adhesion was confirmed by confocal and scanning electron microscopy (SEM). A cecal fistula was created in 22 Wistar rats by incising the cecum and suturing the opening to the surgical wound subcutaneously with four separate stitches. The animals were randomly allocated to three groups: control (CG)-five animals, EF performed; injection (IG)-eight animals 1 × 10(6) ATMSCs injected around EF borders; and suture filament (SG): nine animals, sutured with 1 × 10(6) ATMSCs attached to the filaments with fibrin glue. Fistulas were photographed on the operation day and every 3 days until the 21st day and analyzed by two observers using ImageJ Software. RESULTS Confocal and SEM results demonstrated ATMSCs adhered to SF (ATMSCs-SF). The average reduction size of the fistula area at 21st day was greater for the SG group (90.34%, P < 0.05) than the IG (71.80%) and CG (46.54%) groups. CONCLUSIONS ATMSCs adhered to SF maintain viability and proliferative capacity. EF submitted to ATMSCs-SF procedure showed greater recovery and healing. This approach might be a new and effective tool for EF treatment.

Paired evaluation of calvarial reconstruction with prototyped titanium implants with and without ceramic coating

PURPOSE To investigate the osseointegration properties of prototyped implants with tridimensionally interconnected pores made of the Ti6Al4V alloy and the influence of a thin calcium phosphate coating. METHODS Bilateral critical size calvarial defects were created in thirty Wistar rats and filled with coated and uncoated implants in a randomized fashion. The animals were kept for 15, 45 and 90 days. Implant mechanical integration was evaluated with a push-out test. Bone-implant interface was analyzed using scanning electron microscopy. RESULTS The maximum force to produce initial displacement of the implants increased during the study period, reaching values around 100N for both types of implants. Intimate contact between bone and implant was present, with progressive bone growth into the pores. No significant differences were seen between coated and uncoated implants. CONCLUSION Adequate osseointegration can be achieved in calvarial reconstructions using prototyped Ti6Al4V Implants with the described characteristics of surface and porosity.

Thoraco-omphalopagus asymmetric conjoined twins: Report of a case and complete review of the literature

Thoraco-omphalopagus asymmetric conjoined twinning is a rare condition in which a grossly defective foetus (the parasite) is attached to the thorax and upper abdomen of the main foetus (the autosite). We describe a case of thoraco-omphalopagus asymmetric conjoined twins in which the autosite had an associated large-diameter omphalocoele that was successfully separated at our institution. Reconstruction of the resulting abdominal-wall defect was performed using a flap from the gluteal region and the proximal portion of the inferior limb of the parasite, which is demonstrated. In addition, a review of all previously published cases is presented, showing that overall positive results can be obtained in treating this condition and that the presence and degree of cardiac involvement have a major influence on the prognosis.

Mastopexia com uso de implantes associados a retalho de músculo peitoral maior: técnica utilizada na Disciplina de Cirurgia Plástica da Unicamp

ABSTRACTBackground: T he correction of breast ptosis associated with skin sagging and low projection is still a subject of controversy in the literature. This study aims to describe the experience of the Plastic Surgery Department of Universidade Estadual de Campinas (Unicamp) with the technique of mastopexy with breast implants in a double plane and the pectoralis major muscle flap. Methods: A retrospective study of 20 patients with grade II or III mammary ptosis, who underwent surgery between June 2008 and September 2010, was performed. Results: A 9- and 12-month follow-up of patients showed neither breast or chest deformities nor recurrence of ptosis. All patients presented with good breast projection and adequate upper pole fill, with long-lasting and satisfactory results. Conclusions: Mastopexy with breast implants and the pectoralis major muscle flap technique is easy to perform, with a relatively short learning curve, good reproducibility, and satisfactory long-lasting results.

Lower energy and pulse stacking. A safer alternative for skin tightening using fractional CO2 laser.

PURPOSE To evaluate the effect of different energies and stacking in skin shrinkage. METHODS Three decreasing settings of a fractional CO2 laser were applied to the abdomen of Twenty five Wistar rats divided into three groups. Group I (n=5) was histologically evaluated for microthermal zones dimensions. Groups II and III (n=10 each) were macroscopic evaluated with freeware ImageJ for area contraction immediately and after 30 and 60 days. RESULTS No statistical significance was found within microthermal zone histological dimensions (Group I) in all settings studied. (Ablation depth: 76.90 to 97.18µm; Coagulation depth: 186.01 to 219.84 µm). In Group II, macroscopic evaluation showed that all settings cause significant immediate skin contraction. The highest setting cause significant more intense tightening effect initially, contracting skin area from 258.65 to 179.09 mm2. The same pattern was observed in Group III. At 30 and 60 days, the lowest setting significantly sustained contraction. CONCLUSION Lower fractional CO2 laser energies associated to pulse stacking could cause consistent and long lasting tissue contraction in rats.

Neo-onfaloplastia no decurso das abdominoplastias em âncora em pacientes pós-cirurgia bariátrica

INTRODUCTION: In formerly morbidly obese individuals, major weight loss after bariatric surgery leads to the development of extensive areas of sagging skin with large fat deposits that mainly affect the limbs, several regions of the trunk, and the anterior abdominal wall in particular. The gold standard procedure, anchor-line abdominoplasty (also known as inverted T), is performed with the simultaneous removal of the navel followed by neo-umbilicoplasty during surgery. In the present report, we describe our experience with neo-omphaloplasty in anchor-line abdominoplasty performed in patients who previously underwent bariatric surgery. The neo-omphaloplasty mainly consists of 2 skin flaps bilaterally positioned at the extremities of the skin incision, facilitating a natural appearance of the navel after they are sutured to the fascia. METHODS: From March 2011 to June 2012, 50 patients, who previously underwent bariatric surgery and had stable body weight for at least 6 months, were operated on at the Plastic Surgery Service of the Clinics Hospital of the Faculty of Medicine of the University of Campinas. RESULTS: In the 50 patients, the neo-umbilicus was positioned at a location that was preoperatively established, and these patients exhibited characteristics similar to individuals who had not undergone abdominal surgeries. There was no evidence of dehiscence, necrosis, stenosis, suture line enlargement in the neo-umbilicus, or seroma formation in this cohort. CONCLUSIONS: When neo-omphaloplasty is performed using 2 skin flaps conventionally positioned in the abdominal wall, at a distance varying between 16 and 18 cm from the xiphoid process, the aesthetic outcomes are similar to the natural appearance of the navel. This technical approach is quick and easy to implement.