Tissue Expansion Procedure Research Articles

The Effects of the COVID-19 Mask Mandate on Complication Rates in Postmastectomy Tissue Expansion.

Tissue expansion is a commonly used breast reconstructive strategy. Although the procedure is regarded as safe, tissue expander to implant-based breast reconstruction is reported to have the highest rates of postoperative infection among plastic surgery operations. During the COVID-19 pandemic, face masks were required at all hospital facilities at our institution. The purpose of this study is to investigate the effects of COVID-19 mask mandate on in-office breast tissue expansion procedures. An institutional review board-approved, retrospective review was completed on all patients who underwent unilateral or bilateral tissue expansion following mastectomy at a single institution in 2017 (prior to the COVID-19 mask mandate) and 2021 (following implementation of the mandate). Variables included were demographics, procedure information, and postoperative outcomes. The analysis included 118 patients in the premandate group and 147 patients in the postmandate group. There was no difference in age, body mass index, smoking status, or diabetes mellitus between the 2 groups (P > 0.05). More patients in the postmandate group underwent bilateral reconstruction as opposed to unilateral when compared with the premandate group (70.7% vs 55.9%, P = 0.014). There were no differences in major complication rate (26.3% vs 30.6%, P = 0.495) or minor complication rate 30.5% vs 26.5%, P = 0.495) between the pre-mask and post-mask mandate groups. Our results demonstrated that the use of face masks did not play a significant role in complication rates relating to in-office tissue expansion procedures. It remains up to the discretion and comfortability of the provider if masks should be worn during the procedure.

Patient-reported outcomes of nipple reconstruction with a composite graft from the contralateral nipple

Background Local flap techniques are commonly employed for nipple reconstruction. This study was conducted to present the surgical outcomes of composite nipple grafts performed in patients for whom local flap techniques were not suitable.Methods This study included 26 patients who underwent composite nipple grafting between February 2014 and March 2021. Data regarding demographics and complications were obtained through retrospective chart review. Complications, including wound dehiscence and total or partial necrosis, were evaluated by the surgeon. The BREAST-Q survey (as described by Spear et al.) was utilized to investigate patient satisfaction with the reconstructed nipple as well as donor-site morbidity.Results No instances of wound dehiscence, infection, implant exposure, or total necrosis were noted. However, partial necrosis was observed in five patients (19.2%) and healed well with local wound care. The odds ratio (OR) for partial necrosis was not significantly higher in patients who received radiotherapy than in those who did not (OR=1.06, P=0.97). The color and projection of the reconstructed nipple were generally found to be satisfactory. Regarding donor-site morbidity, sensation and contractility were well preserved.Conclusions This study demonstrated that composite nipple grafting is a viable option, as it reduces the size of the relatively large nipple on the normal side while preserving nipple sensation and contractility. This technique can be applied using a thin skin flap that covers the prosthesis following irradiation or a tissue expansion procedure, with minimal risk of compromising the nipple.

Surgical delay increases the survival of expanded random-pattern flap in pediatric patients

Despite the aid of tissue expansion, the ideal design of random pattern flap is not always available in patients with extensive skin lesions. We investigated the effectiveness of surgical delay on expanded flaps in pediatric patients. Retrospective cohort study was performed on patients who underwent tissue expansion surgery for extensive skin lesions at Seoul National University Children’s Hospital. The surgical delay technique was employed for patients with unfavorable flap conditions related to location or transposition angles. The dimensions of skin lesions and flaps were measured based on medical photographs. Fifty patients underwent a total of 66 tissue expansion procedures (49 conventional procedures among 41 patients, 17 surgical delay procedures among 15 patients) from January 2016 to September 2019. Although flaps in the surgical delay group were more narrow-based (p < 0.001), the partial flap loss rate and excised area-to-inflation amount ratio was comparable between the two groups (p = 0.093 and p = 0.194, respectively). Viable flaps, excluding postoperative necrosis, in the surgical delay group were significantly more narrow-based in terms of the length-to-base width ratio and the area-to-base width ratio compared to conventional group (p < 0.01, p < 0.01). Surgical delay can result in outcomes comparable to well-designed random flaps, even in disadvantageous conditions. Patients with large skin lesions but limited areas for expansion may benefit from surgical delay.

Non-Invasive in Vivo Quantification of Directional Dependent Variation in Mechanical Properties for Human Skin.

Skin is the body’s largest organ, and it shows non-linear and anisotropic behavior under the deformation. This behavior of the skin is due to the waviness and preferred orientation (in a particular direction) of collagen fibers. This preferred orientation of collagen fibers results in natural pre-tension and anisotropy of the skin. The knowledge of natural skin pre-tension and anisotropy is essential during incisions and surgery. The available suction-based devices quantify the anisotropy through the displacement field and cannot measure the stress-strain relation in particular directions. Therefore, in the current study, an in vivo full-field measurement suction apparatus was developed to measure the stress and strain of skin in all planar directions through a single experiment. First, this apparatus was tested on silicone substrates of known properties, and then it was used to test the skin of 12 human forearms. Further, to check the effect of hand stability on the measurements, the obtained results of the skin were compared with the results of a standard test performed in the same skin using a steady setup. The consistency between these two results confirms that the stability of the hand does not influence the measurements of skin properties. Furthermore, using the developed apparatus, the skin’s anisotropy and its relation with the Kraissl’s lines orientation was quantified by measuring the toe and linear moduli at an interval of one degree. The minimum and maximum values of the toe and linear moduli were 0.52 ± 0.09 and 0.59 ± 0.11 MPa, and 3.09 ± 0.47 and 5.52 ± 1.13 MPa, respectively. Also, the direction of maximum moduli was found almost similar to Kraissl’s lines’ orientation. These results confirm the contribution of skin pre-tension on the anisotropy of the skin. The present apparatus mimics the tissue expansion procedure, where observation of the test may be helpful in the selection of size and shape of the expander.

Establishment and validation of a clinical prediction model for infection risk at the placement sites of skin and soft tissue expanders

Objective: To establish a clinical prediction model for infection risk at the placement sites of skin and soft tissue expanders (hereinafter termed as expanders) and to validate the predictive value of the model. Methods: A retrospective observational study was conducted. Totally 2 934 patients who underwent skin and soft tissue dilatation surgery in the Department of Plastic Surgery of the First Affiliated Hospital of Air Force Medical University from January 2009 to December 2018 and met the selection criteria were included. There were 1 867 males and 1 067 females, with a median age of 18 years. Totally 3 053 skin and soft tissue expansion procedures were performed with 4 266 expanders implanted. The following indexes were selected as predictor variables, including patients' age, gender, marital status, ethnicity, hospital admission, surgical indication, disease duration, with/without history of smoking, history of drinking, history of blood transfusion, history of underlying diseases, and inability to use cephalosporin antibiotics due to allergy, number of expander in a single placement, rated volume of expander, water injection rate of expander in the first time, placement site of expander, anesthesia method, duration of operation, and with/without postoperative hematoma evacuation, and infection at the placement site of expander as the outcome variable. Univariate analysis of the data was performed using least absolute shrinkage and selection operator (LASSO) regression to screen the potential risk factors affecting infection at the placement sites of expanders, the factors selected by the univariate analysis were subjected to binary multivariate logistic regression analysis to screen the independent risk factors affecting infection at the placement sites of expanders, and a nomogram prediction model for the occurrence of infection at the placement sites of expanders was established. The C index and Hosmer-Lemeshow goodness of fit test were used to evaluate the discrimination and accuracy of the model, respectively, and the bootstrap resampling was used for internal verification. Results: The results of LASSO regression showed that age, gender, hospital admission, surgical indication, disease duration, history of drinking, history of heart disease, history of viral hepatitis, history of hypertension, inability to use cephalosporin antibiotics due to allergy, number of expander in a single placement, rated volume of expander, placement site of expander, postoperative hematoma evacuation were the potential risk factors for infection at the placement sites of expanders (regression coefficient=-0.005, 0.170, 0.999, 0.054, 0.510, -0.003, 0.395, -0.218, 0.029, 0.848, -0.116, 0.175, 0.085, 0.202). Binary multivariate logistic regression analysis showed that male, emergency admission, disease duration ≤1 year, inability to use cephalosporin antibiotics due to allergy, rated volumes of expanders ≥200 mL and <400 mL or ≥400 mL, and expanders placed in the trunk or the limbs were the independent risks factors for infection at the placement sites of expanders (odds ratio=1.37, 3.21, 2.00, 2.47, 1.70, 1.73, 1.67, 2.16, 95% confidence interval=1.04-1.82, 1.09-8.34, 1.38-2.86, 1.29-4.41, 1.07-2.73, 1.02-2.94, 1.09-2.58, 1.07-4.10, P<0.05 or P<0.01). The C index for evaluating the discriminative degree of the model was 0.63, the Hosmer-Lemeshow goodness of fit test for evaluating the accuracy of the model showed P=0.685, and the C index for internal validation by the bootstrap resampling was 0.60. Conclusions: Male, emergency admission, disease duration ≤1 year, inability to use cephalosporin antibiotics due to allergy, rated volume of expander ≥200 mL, and expanders placed in the trunk or the limbs are the independent risk factors for infection at the placement sites of expanders. The clinical prediction model for infection risk at the placement sites of expanders was successfully established based on these factors and showed a certain predictive effect.

Transcriptomic analysis reveals dynamic molecular changes in skin induced by mechanical forces secondary to tissue expansion

Tissue expansion procedures (TE) utilize mechanical forces to induce skin growth and regeneration. While the impact of quick mechanical stimulation on molecular changes in cells has been studied extensively, there is a clear gap in knowledge about sequential biological processes activated during long-term stimulation of skin in vivo. Here, we present the first genome-wide study of transcriptional changes in skin during TE, starting from 1 h to 7 days of expansion. Our results indicate that mechanical forces from a tissue expander induce broad molecular changes in gene expression, and that these changes are time-dependent. We revealed hierarchical changes in skin cell biology, including activation of an immune response, a switch in cell metabolism and processes related to muscle contraction and cytoskeleton organization. In addition to known mechanoresponsive genes (TNC, MMPs), we have identified novel candidate genes (SFRP2, SPP1, CCR1, C2, MSR1, C4A, PLA2G2F, HBB), which might play crucial roles in stretched-induced skin growth. Understanding which biological processes are affected by mechanical forces in TE is important for the development of skin treatments to maximize the efficacy and minimize the risk of complications during expansion procedures.

Directional dependent variation in mechanical properties of planar anisotropic porcine skin tissue

Nonlinear and anisotropic mechanical behavior of skin is essential in various applications such as dermatology, cosmetic products, forensic science, and computational studies. The present study quantifies the mechanical anisotropy of skin using the bulge method and full-field imaging technique. In bulging, the saline solution at 37 °C mimics the in vivo body temperature and fluid conditions, and all experiments were performed in the control environment. Assumption of thin spherical shell membrane theory and imaging techniques were implemented to obtain the anisotropic stress strain relations. Further, stress strain relations at an interval of 10° were calculated to obtain the variation in modulus with direction. Histological examinations were performed to signify the role of the collagen fibers orientation on the mechanical properties. The maximum and minimum linear modulus and collagen fiber orientation intensity were found in good agreement. The angular difference between maximum and minimum linear modulus and orientation intensity was found 71° ± 7° and 76° ± 5° respectively, and the percentage difference was 43.4 ± 8.2 and 52.5 ± 6.4 respectively. Further, a significant difference in the maximum and minimum collagen orientation intensity between the untested and tested specimens indicates the realignment of the fibers. Additionally, a cubic polynomial empirical relation was established to calculate the quantitative variation in the apparent modulus with the directions, which serves for the anisotropic modeling of the skin. The experimental technique used in this study can be applied for anisotropic quantification of planar soft tissues as well as can be utilized to imitate the tissue expansion procedure used in reconstructive surgery.

Mechanical stretching stimulates growth of the basal layer and rete ridges in the epidermis.

We have developed four experimental models of mechanical stimulation applied to the back skin using tissue expansion (TE) procedure performed on minipigs. The technique is used by plastic surgeons for decades, to amend the congenital or accidental skin defects, though underlying changes in epidermis are not well understood. We found that the initial stretching increased proliferation of basal keratinocytes leading to elongation of the basal layer, and increased cellular density. The increased number of the rete ridges, suggests that they absorbed the impact of excessive proliferation, preserving layered organization of epidermis. We found β1 integrin to be a very sensitive responder to stimulation instigated by TE procedure, able to dynamically relocate to adjust the basal cell against external force. Repeated mechanical stimulation with a seven-day interval generated healthy tissue without detrimental effects. Given the similarities between the structure of the porcine and human epidermis, we speculate that a similar mechanism functions in human skin. A better understanding of the underlying process could help improve medical care and outcomes for patients undergoing surgical reconstruction.

Introduction of a novel guided bone regeneration memory shape based device.

Bone regeneration by periosteal distraction has been reported in numerous animal studies; however, the main disadvantages of this technique are poor bone quality and soft tissue invasion in the distracted space. The purpose of this study was to evaluate a novel shape memory-based device to promote bone regeneration in a large, secluded growth space in a rabbit model. Twenty rabbits were divided into two groups. In the first group (n = 10), a device composed of silicone sheets and nitinol strips was inserted subperiosteally in the calvarial area. In the second group (n = 10), only silicone sheets were inserted in the calvarial area. Each group was further divided in half: five animals were sacrificed at 8 weeks postoperatively, and the other five were sacrificed at 16 weeks postoperatively. In the study group, the new device vertically expanded the overlying soft tissue 4 mm above the original bone and created a secluded space; the newly generated bone maximum height median ranged between 2.7 mm in 8 weeks group and 2.6 mm in 16 weeks group. In the control group, a very thin rim of bone was generated below the flat silicone sheets on top of the original bone. Maximum bone heights median ranged from 0.37 mm in 8 weeks group to 0.32 mm in 16 weeks group. The device was proven to be effective at vertically augmenting bone by applying the guided bone regeneration and soft tissue expansion procedures simultaneously. This device may pave the way for a new generation of smart guided bone regeneration membranes that can remember the original dimensions of resorbed bone areas.

The application of L-PRP in AIDS patients with crural chronic ulcers: A pilot study

PurposeNonhealing wounds or skin ulcerations are the result of insufficient repair and destruction of a local healing potential. Opportunistic infections which cause a lot of ulcer complications influence the worsening general condition of patients with AIDS, ultimately leading to death. The chronicity of the condition and poor results of conventional therapy have prompted the search for new methods of treatment. Materials and methodsWe have examined venous or arteriovenous insufficiency-related extensive crural ulcers in AIDS patients. Crural ulcer healing processes were evaluated with clinical observations and histopathological, immunohistochemical and molecular examinations of tissue samples harvested from the wound edges before and on day 10 after L-PRP cover dressing. ResultsClinical observations showed positive effects of L-PRP in all patients. However, complete wound closure was noted in 60% of cases. Statistical analysis of histological examination showed increased epidermal processes between samples, but the difference was nonsignificant. However, immunohistochemical investigations showed an increased healing process with strong statistical significance. The mean VEGF level before L-PRP usage was 114.3 vessels/mm2 and on day 10 118.9 (p=0.001523). The mean FLK level was 103.2 and 109.9 respectively (p=0.008241). The biggest differences were observed for CD34, with values of 68.2 on day 0 and 100.8 on day 10 (p=0.006982). Molecular analysis generally showed decreased gene expression and confirmed vascular formation and reepithelialization processes. ConclusionsIn our opinion, L-PRP may be used to eradicate microorganisms from wounds, to induce neovascularization, and in unhealed cases prepare the base and edge of the ulcer for skin grafting and tissue expansion procedures.

Outcome of 122 delayed breast reconstruction following post-mastectomy radiotherapy: The scarless latissimus dorsi flap with tissue expansion technique

Delayed breast reconstruction with tissue expansion may be risky after radiotherapy, due to the poor skin quality. To permit the use of the tissue expansion procedure, we propose a scarless latissimus dorsi flap to bring tissue trophicity, by a healthy vascularized muscular interface with no donor scar and no patch effect. The objective of this study is to assess the outcome of the tissue expansion technique with scarless latissimus dorsi flap after post-mastectomy radiotherapy. All the patients who had benefited of a delayed breast reconstruction after radiotherapy using tissue expansion technique with scarless latissimus dorsi flap, between January 2000 and January 2013, were reviewed. The exclusion criteria were: prior breast reconstruction, or interruption of breast reconstruction procedure due to active metastatic disease requiring ongoing oncological treatment. The complications were identified: failures of reconstruction, implant exposure, wound dehiscence, capsular contracture, deflation of implant, hematoma, infection, and skin necrosis. One hundred and twenty-two breasts were reviewed. The average time between the flap and the expander intervention was: 194±114SD (28-1051) days. The mean volume of inserted expander was 633±111SD (350-1100) mL and the mean inflation volume was 578±190SD (170-1160)mL. The average time between insertion of the expander and insertion of the permanent implant was 132±76SD (49-683) days. The mean inflation of the implant volume was 368±105SD (130-620) mL. Forty patients developed at least one complication. The most common complication was the appearance of a capsular contracture requiring a capsulectomy: 11 (9.2%) with permanent implants and 6 (4.9%) with expander. Deflation of implants occurred with six permanent implants and with one expander. There were 3 breast reconstructions failures (two infections and one exposure of implants). This procedure offers the advantages that there is no unattractive scar, and that there are low rates of exposure or failed reconstruction.

Results from the ASPIRE study for breast reconstruction utilizing the AeroForm™ patient controlled carbon dioxide-inflated tissue expanders

Therapeutic or prophylactic mastectomy is often indicated for women with breast cancer, or for those at a high risk of developing cancer due to familial history or genetic mutations. Favorable aesthetic and psychological results make prosthetic reconstruction of the breast with placement of tissue expanders followed by permanent implant a popular choice for women diagnosed with breast cancer. This study describes the results of the ASPIRE trial, the objective of which was to provide supportive data to demonstrate the performance and safety of the AeroForm™ System in a population with broader selection criteria than previous studies. Results of the earlier PACE clinical studies (PACE 1 and 2) demonstrated that the AeroForm™ System could be used safely and effectively to achieve the desired expansion necessary for successful breast reconstruction. In the current ASPIRE trial described in the paper, performance of the device was evaluated by successful tissue expansion and exchange to breast implant(s) unless precluded by a non-device related event. Safety data was evaluated based on reported adverse events. A prospective, single center, open-label study in which subjects who met the inclusion criteria and agreed to participate were enrolled and implanted with the AeroForm expander either at the time of mastectomy (immediate) or sometime after mastectomy (delayed). In the event of a bilateral procedure, the expander was implanted in each side. Subjects were followed until the explant of the tissue expander(s) and exchange for silicone or saline breast implant(s). Thirty-four expanders were placed in 21 subjects in the clinical trial; the average age of subjects was 49.7 ± 8.6 years with average BMI of 26.1 ± 4.7. Bilateral procedures accounted for 62% of the total and 88% of the reconstructions were completed with a latissimus dorsi flap (anterior approach) per the investigators standard procedure. Four (12%) of the cases (12%) were completed in two subjects using an inferior dermal flap. Overall success rate was 94% (32/34 breasts) with no device related reconstruction failures. Two subjects failed reconstruction, one due to infection and one due to wound healing issues, both requiring unilateral expander removal and revision surgery. However, successful second stage reconstruction was completed in both subjects in a delayed procedure. The ASPIRE trial reports confirmatory data in a more inclusive patient population than the previous PACE 1 and 2 trials, indicating that the AeroForm Expander, provides a time-saving, needle-free, safe and effective method of tissue expansion for breast reconstruction. There were no device related complications that precluded the subjects from achieving the study goal of a permanent implant exchange. Reported complications are similar to those reported in the literature for tissue expansion procedures. Further development may enable a single dose controller to operate both expanders in a bilateral patient and increase the size range offered with this promising technology.

Aesthetic Reconstruction of Congenital Cerebriform Intradermal Nevus by Sequential Tissue Expansion at an Early Age: Ten-year Follow-up

DOI: 10.7247/jiumf.19.3.9 Cerebriform intradermal nevus (CIN) is a congenital tumoral abnormality of the scalp. The incidence of development of malignant melanoma in CIN can rise up to 10%. Surgical excision of the lesion is the sole treatment modality for CIN. In this case, we present the 10year follow-up of a 45-day-old infant with congenital CIN covering 75% of his scalp who had scalp reconstruction by sequential tissue expansion. Sequential tissue expansion processes with rectangular-shaped expanders of 450, 400, and 250 ml in size, respectively, were applied over an eight-month period. The interval between the two procedures was two weeks. The tissue expansion technique is a useful option for hair-bearing scalp reconstruction. This technique can be used sequentially or gradually. In order to obtain homogenous follicle distribution, the rest of the scalp should be expanded as much as possible. Careful planning in large defects helps prevent complications. In this case, we applied a sequential tissue expansion procedure when the patient was 45 days old, and the expansion period was continued for eight months. This very early age is a unique case for tissue expansion applications when compared with examples in the literature. On the other hand, we want to underline the aesthetic result of this case rather than the reconstructive method. Reconstruction of huge scalp defects by re-expansion (sequential expansion) and leaving the expander beneath the expanded flap until the sequential procedure decrease flap contracture reduces the required number of operations, and produces better aesthetic outcomes.

Reverse tissue expansion by liposuction deflation for revision of post-surgical thigh scars

Scars hypertrophy and widen when stretching mechanical forces are applied to resilient newly formed collagen before it reaches final maturity marring the final result of many surgical procedures and resulting in a clinical problem for many patients. Scar revision by surgical excision remains the traditional treatment for hypertrophic or widespread scars. It relies upon recruitment of local tissues for closure of the ensuing defect. Providing tension-free skin closure is the best option to avoid recurrence. Although tissue expansion procedure is a valuable and reliable technique for scar revision, it has its own disadvantages and potential complications. We describe an alternative method for scar revision that may be applicable in certain situations. Instead of expanding the soft tissues to make available additional skin, deflation by liposuction may be affected to relax the skin envelope thus indirectly providing additional skin for scar revision. We call this method 'reverse tissue expansion'.

16- EVALUATION OF USING TISSUE EXPANDER FOR RECONSTRUCTION OF POST BURN ALOPECIA OF SCALP

Tissue expansion represents one of the major advances in surgery and is particularly applicable to burn reconstruction. The technique provides tissue of similar texture and color to the defect to be covered and has the added advantage of minimal donor site morbidity. This study aimed to assess the results & complications in the correction of post burn scalp alopecia using a tissue expansion, prevention of implant extrusion, lower the infection rate in tissue expansion and expander selection. Forty patients with scalp burn alopecia treated with tissue expansion of the scalp, were included in this prospective study in Sulaimania hospital of burn and reconstructive surgery from February 2002 to September 2009 with age groups ranging from (4-30) years with an average of 15.5 years. Twenty three patients were females. The time period between burn injury and reconstruction ranged between (4-25) years, their scalp defects ranging between (5x10cm -13x25cm). We were able to completely reconstruct 77.5% of the total patients with single or multiple sessions of expansions. The remaining 22.5% patients have benefited from reduction in the percentage of alopecia and recreation of anterior hair line to camouflage their defects. Major complications occurred in 6 cases(15%), in which the expansion process interrupted with removal of the expander. In conclusion, It is not always possible to measure the absolute efficacy of a surgical technique or determine a general guideline its indication of the tissue expansion procedure although afflicted with a broad range of possible complications, the tissue expansion procedure remains a valuable and reliable technique for the reconstruction of post burn alopecia of the scalp.

Retrospective analysis of tissue expansion in reconstructive burn surgery: Evaluation of complication rates

Tissue expansion is a widespread and accepted concept in reconstructive surgery, but is also afflicted with a variety of complications. In burn patients, this technique allows large areas of burn scar to be replaced by tissue of similar texture and colour to the defect. We retrospectively reviewed our results with tissue expanders in 57 burn patients over a period of 8 years including 102 expanders. Statistical analyses revealed a significant influence of the anatomical region ( p = 0.0156; Chi-square = 15.6811) and of the expander volume ( p = 0.0417; Chi-square = 18.8918) on the failure rate outcome. Factors such as age, gender, number of expanders per patient and shape of expander showed no statistical correlation in relation to the failure rate ( p-values >0.05). Furthermore, we present a short review of the recent literature of complications after tissue expansion. The presented study may help to draw attention on different aspects in tissue expansion and critically focus on each step of the tissue expansion procedure from implantation over inflation to explantation.

Three‐dimensional power Doppler in the diagnosis and surgical management of thoraco‐omphalopagus conjoined twins

We report the case of a 28-year-old primigravida in whom we diagnosed thoraco-omphalopagus conjoined twins at 23 weeks' gestation. Further examination revealed a shared liver and separate gall bladders. The twins shared a single umbilical cord. This raised the possibility of sharing of the major intrahepatic vasculature, which could preclude surgical separation. Three-dimensional (3D) power Doppler examination of the hepatic and funic vasculatures was performed using a Voluson ultrasound machine (GE Healthcare Technologies, Milwaukee, WI, USA), equipped with a 3.5-MHz automatic-sweeping transabdominal E8 transducer (Figure 1). This revealed a single three-vessel umbilical cord. The umbilical vein bifurcated into each fetus's hepatic vein, as shown in Figure 2. No major vascular anastomoses were found between the livers of each twin. After extensive counseling, the couple opted for continuation of pregnancy, followed by Cesarean section at 36 weeks' gestation. Postnatal magnetic resonance imaging (MRI) revealed no major shared intrahepatic vasculature. After a tissue expansion procedure, surgical separation was performed successfully at 8 months of age without immediate serious damage to either twin. No major intrahepatic vascular anastomoses were found intraoperatively. Three-dimensional power Doppler image (color mode i.e. with soft tissue subtraction) showing major intra-abdominal and intrahepatic vessels. CHA, common hepatic artery; HA, hepatic artery; HV, hepatic vein; IVC, inferior vena cava; PV, portal vein. Three-dimensional power Doppler image (glass body mode) showing a single umbilical cord with an absence of intrahepatic shared vasculature. HV, hepatic vein; UV, umbilical vein. The chance of successful postnatal separation of conjoined twins depends on the complexity of vital organ fusion1. For omphalopagus twins, the degree of fusion of the hepatobiliary and gastrointestinal systems is not easy to determine prenatally and can pose a significant surgical challenge2. In one reported case, the major vascular connections within a shared liver were demonstrated postnatally and this significantly affected the surgical procedures that were performed3. Portal veins can be demonstrated by Doppler examination in 94% of fetuses that are more advanced than 20 weeks' gestation4, which implies that sonographic examination should be able to identify any major vascular connections from this gestational age onwards. The advent of power Doppler ultrasonography, in combination with 3D imaging, has allowed visualization of the intrahepatic vasculature in multiplanar and simulated 3D images. 3D imaging of vascular structures can also be accomplished using high-definition color Doppler. This report suggests a further application of these novel imaging technologies in the management of conjoined twins and other complex vascular malformations. 3D imaging technology allowed the examiner to visualize the target organs from limited insonation angles, which are commonly encountered during the examination of multifetal pregnancies. MRI offers an alternative method of investigating shared vasculature in the liver5. It provides sharp soft tissue delineation, but, owing to the complicated protocol and cost, MRI should be reserved for patients for whom it is not possible to obtain optimal images on ultrasound examination. 3D sonographic vascular imaging has clear advantages in terms of its noninvasiveness and convenience, and is also more suitable for use in patients who suffer from claustrophobia. T. Wataganara*, A. Sutanthaviboon*, S. Ngerncham , C. Vantanasiri*, * Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Prannok Road, Bangkoknoi, Bangkok, Thailand 10700, Division of Neonatology, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Prannok Road, Bangkoknoi, Bangkok, Thailand 10700

Effects of antineoplastic agents on the peripheral nerves under a surgical tissue expansion procedure: An experimental study

Elongation of peripheral nerve by the use of a tissue expander is helpful to repair nerve defects. This study was designed to investigate the effects of some antineoplastic agents on the peripheral nerves under a surgical tissue expansion procedure. Twenty-five Wistar rats were used in this study. Following the exposition of the sciatic nerve and placement of two 10/0-nylon sutures in the epineurium 20 mm apart, a tissue expander was then placed under it. Inflation of the expander was immediately accomplished by the separate percutaneous injections of 6, 6, and 8 ml for every 3 min under general anesthesia. The expander was fully deflated at the end of each 3 min The distance between two sutures was measured 1 h later to measure the rate of elongation. Rats were randomly divided into five groups (according to the administered drugs), each consisting of five rats (10 sciatic nerves). Normal saline (1 ml) in the control group (group I), cyclophosphamide (15 mg/kg) in the group II, cisplatinum (3 microg/kg) in the group III, mitomycin-C (0.5 mg/kg) in the group IV and 5-fluorouracil (10 mg/kg) in the group V were injected intravenously. Intravenous injections of drugs were performed via the tail vein 30 min before expansion, 48 and 96 h after removal of expander. The incision was reopened on the third and seventh postoperative days, and five sciatic nerves of each group were exposed and then the pinching test was performed to measure regeneration distance. Electroneurographic changes were recorded. The expanded portion of the sciatic nerve between two sutures was harvested for histological evaluation. There is no significant difference between the elongation rates of all groups (P < 0.05). Histologic evaluation showed that inflammatory changes, vacuolization, intraneural edema, demyelination, axonal changes in the control group, the cisplatinum group, and the mitomycin-C group. These changes were significantly decreased in the cyclophosphamide group and the 5-fluorouracil group. In the cyclophosphamide group and the 5-fluorouracil group, the amplitude of compound action potential (CAP) values were significantly higher and the latency was significantly shorter (P > 0.05). We believed that cyclophosphamide and 5-fluorouracil may be helpful in tissue expansion of peripheral nerves, by decreasing the effects of the ischemia-reperfusion injury on the expanded peripheral nerves.

Tissue expander complications in plastic surgery: a 10-year experience.

Tissue expanders have been of great value in plastic surgery. Tissue expansion was developed for a specific indication; however, within a very short time, the concept of tissue expansion found wide applicability. From 1990 to 1999, 315 expanders in 164 patients were utilized. A retrospective analysis of complications and prognostic factors for complications were done. The indications for tissue expansion were burns (50%), trauma (32%), and sequelae of previous surgery (8.8%). The expanders were inserted most frequently in the scalp, trunk and neck. There were 22.2% of complications and the most common were expander exposure (50%), infection (24%) and bad function of the expander (12.8%). The present study revealed an increased rate of minor complications in the group of 0 to 10 years of age and an increased rate of major complications for face and neck expansions compared to trunk expansion. There were no increased complication rates for the other age and anatomic site groups, previous expansion, concomitant expansion and type of expander used. The outcomes from tissue expansion procedures done in our hospital are similar to those reported in the literature. Tissue expansion is a good and safe technique.

Long-term results of total knee arthroplasty after the use of soft tissue expanders.

The success of total knee arthroplasty can be jeopardized by poor wound healing. In the current study, the results of knee arthroplasty after soft tissue expansion were reviewed retrospectively in 27 patients (29 knees) at risk for problematic healing. The incidence of wound complications was recorded for all patients after the expansion procedure and the arthroplasty. A Knee Society score also was calculated at the latest evaluation. Minor wound complications occurred after 21% (six of 29) of the tissue expansion procedures and after 18% (five of 28) of the subsequent arthroplasties. One major wound complication occurred during tissue expansion necessitating abandonment of the planned arthroplasty. No major wound complications occurred in those patients who underwent knee arthroplasty. At an average followup of 34.4 months, the average Knee Society score was 83.7 points. The results of the current study show that the technique of soft tissue expansion before total knee arthroplasty in patients at high risk for wound healing problems can successfully prevent catastrophic wound complications after the arthroplasty procedure and can avoid the need for disfiguring soft tissue reconstructions.