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Heparin use, both prophylactically and therapeutically, is prevalent among hospitalized patients. Patients on heparin may develop a thrombocytopenia that is self-limited. Fewer patients develop a heparin-induced thrombocytopenia that can cause severe bleeding and thrombosis owing to intravascular platelet aggregation. The authors present a case report of heparin-induced thrombocytopenia in a patient who underwent aortic arch and aortic valve replacement that resulted in bilateral above-knee amputations. The patient developed limb ischemia related to heparin-associated thrombosis, but had a delay in antibody seroconversion. Early and accurate diagnosis of heparin-induced thrombocytopenia requires a high clinical suspicion and may be present despite the absence of serum antibodies. [ABSTRACT FROM AUTHOR]

The potential for human adipose-derived mesenchymal stem cells (AMSC) to traffic into various tissue compartments was examined using three murine xenotransplantation models: nonobese diabetic/severe combined immunodeficient (NOD/SCID), nude/NOD/SCID, and NOD/SCID/MPSVII mice. Enhanced green fluorescent protein was introduced into purified AMSC via retroviral vectors to assist in identification of cells after transplantation. Transduced cells were administered to sublethally irradiated immune-deficient mice through i.v., intraperitoneal, or subcutaneous injection. Up to 75 days after transplantation, tissues were harvested and DNA polymerase chain reaction (PCR) was performed for specific vector sequences as well as for human Alu repeat sequences. Duplex quantitative PCR using human beta-globin and murine rapsyn primers assessed the contribution of human cells to each tissue. The use of the novel NOD/SCID/MPSVII mouse as a recipient allowed rapid identification of human cells in the murine tissues, using an enzyme reaction that was independent of surface protein expression or transduction with an exogenous transgene. For up to 75 days after transplantation, donor-derived cells were observed in multiple tissues, consistently across the various administration routes and independent of transduction parameters. Tissue localization studies showed that the primary MSC did not proliferate extensively at the sites of lodgement. We conclude that human AMSC represent a population of stem cells with a ubiquitous pattern of tissue distribution after administration. AMSC are easily obtained and highly amenable to current transduction protocols for retroviral transduction, making them an excellent avenue for cell-based therapies that involve a wide range of end tissue targets.

Annular pancreas is an uncommon congenital anomaly associated with duodenal atresia in neonates. Rarely, the condition may manifest later in life. These symptoms include abdominal pain, nausea, and vomiting and usually arise due to obstruction to gastric emptying. Abdominal CT scan with high resolution and angiography protocol and magnetic resonance imaging are useful in confirming the presence of annular pancreas. Operative management involves bypassing the obstructed duodenum. Duodenoduodenostomy is routinely performed in neonates with annular pancreas. In adults, the duodenum is less mobile, and duodenojejunostomy or gastrojejunostomy are recommended. We report two cases of annular pancreas in adults treated with laparoscopic gastrojejunostomy.

Giant omphalocele is associated with a high degree of visceroabdominal disproportion, which prohibits safe primary closure. Conventional treatment options include (1) topical therapy with epithelialization followed by secondary ventral hernia repair and (2) staged reduction using a SILASTIC(R) (Dow Corning, Midland, MI) chimney. The authors report a case in which staged reduction of a giant omphalocele was facilitated by the use of crescent-shaped tissue expanders positioned in the potential space between the internal oblique and transversus abdominis layers of the abdominal wall.

Intestinal tissue engineering has the potential of developing new treatment strategies for patients with a deficit in intestinal surface area. The purpose of this study was to investigate the capacity of small intestine submucosa (SIS) to regenerate intestinal epithelia in a rodent model for a duodenal defect. A duodenotomy was created in 20 Sprague-Dawley rats and was repaired with a circular patch of SIS. The repaired sites were retrieved 1, 2, 4, and 12 weeks after implantation. The size of the residual mucosal defect was measured. The retrieved tissues were fixed in formalin and processed by standard histologic techniques. The animals tolerated the procedure well. The mean size of the mucosal defects significantly decreased with time. Complete epithelialization of the defects was noted within 4 weeks in three of five samples. Histologically, the defects were lined with crypts and villi, but the muscularis layer did not regenerate. In the rodent model, SIS can be used as a patch to repair a duodenotomy. Mucosal regeneration was observed in the area of the defect. Further studies will determine whether SIS may be used to preserve or increase mucosal surface area in patients whose bowel length is compromised.

Purpose: Antegrade continence enemas (ACE) are an efficacious therapeutic option for patients with fecal incontinence. The authors review their institution's experience with a variation of the Monti-Malone ACE procedure using the left colon as a source of an intestinal conduit and enema reservoir., Methods: From 2000 to 2002, 18 patients with fecal incontinence or intractable constipation underwent left-colon ACE (LACE) procedure. Concomitant Mitrofanoff appendicovesicostomy was performed in 15 patients and bladder augmentation in 9. The majority of patients had neural tube defects. A segment of left colon was tubularized, tunneled into the muscular wall of the distal colon, and exteriorized through the left upper quadrant or midabdomen. Stomal catherization and enema installation were started one month postoperatively., Results: Fifteen patients (83%) achieved fecal continence, 2 remain incontinent of stool, and 1 experienced stomal closure (mean follow-up was 24 +/- 9 months). Two patients had stomal stenosis that required revision. The mean enema volume in patient's achieving continence was 360 +/- 216 mL, and the mean transit time was 18 +/- 12 minutes., Conclusions: LACE is an efficacious procedure for fecal incontinence that can be performed safely at the time of major urologic reconstruction. Administration of enemas into the left colon has several physiologic advantages that result in predictable bowel evacuation.

Our laboratory has characterized a population of stromal cells obtained from adipose tissue termed processed lipoaspirate cells (PLAs). PLAs, like bone-marrow derived mesenchymal stem cells (BM-MSCs), have the capacity to differentiate along the adipogenic, osteogenic, chondrogenic, and myogenic lineages, In order to better characterize these two multi-lineage populations, we examined the surface phenotype of both bone marrow and adipose tissue-derived cells from five patients undergoing surgery. PLA and BM-MSC cells were isolated, subcultivated, and evaluated for cell surface marker expression using flow cytometry. PLA and BM-MSC cells both expressed CD13, CD29, CD44, CD90, CD105, SH-3, and STRO-1. Differences in expression were noted for cell adhesion molecules CD49d (Integrin alpha4), CD54 (ICAM-1), CD34, and CD106 (VCAM-1). While markedly similar, the surface phenotypes of PLA and BM-MSC cells are distinct for several cell adhesion molecules implicated in hematopoietic stem cell homing, mobilization, and proliferation.

Background: Tracheal stenosis is a challenging surgical problem that can require reconstruction using autologous grafts or artificial stents. In this study, we evaluate the efficacy of Surgisis, a commercially available, biocompatible, acellular matrix, in the repair of a critical-size tracheal defect., Methods: A full-thickness defect (2 mm x 6 mm) was created in tracheal rings 4 through 6 in adult rats. A piece of 8-ply Surgisis (Cook; Bloomington, IN) was sutured to the edges of the defect with interrupted 8-0 polypropylene sutures. In control animals, the defect was closed primarily. The trachea was harvested at 4 weeks and prepared for histologic evaluation using conventional techniques. Cross-sectional area and perimeters were calculated using imaging software., Results: Tracheal defects without patch repair (n = 3) resulted in tracheal stenosis and immediate death. Animals that underwent Surgisis patch repair of tracheal defects (n = 10) tolerated the procedure well and had no audible stridor or evidence of respiratory distress. Eight of ten animals survived 4 weeks. The tracheal lumen was patent with no evidence of contracture or degradation of the Surgisis. Histologically, neovascularization of the Surgisis was noted with moderate inflammation. The surface of the Surgisis patch was covered ith a lining of ciliated epithelial cells., Conclusion: In the rodent model, Surgisis appears to be an efficacious method for the patch repair of partial circumferential tracheal defects. Surgisis appears to be a safe and promising means of facilitating neovascularization and tissue regeneration. The long-term use of Surgisis warrants further investigation.

Background: Robotic technology promises to have an important future in surgery, but few residency programs incorporate robotics into surgical training. We sought to compare the speed and accuracy with which junior residents could perform laparoscopic tasks using both a robotic surgical device (Zeus MicroWrist) and conventional laparoscopic instruments., Methods: Twelve residents performed exercises of progressive difficulty in an inanimate model using both the robot and conventional laparoscopy. Analysis of variance statistical analysis was used to compare task time and suturing accuracy scores., Results: Grasping and suturing exercises were performed significantly faster with conventional laparoscopic instruments than with the robot. However, no difference in task time was noted for intracorporeal knot tying. Accuracy scores for suturing were higher for the robot., Conclusions: Junior residents can be instructed easily and quickly in both robotic and conventional advanced laparoscopic skills. The utility of robotic surgical devices in resident training requires further investigation.

A 3-month-old boy with a history of intermittent stridor was found to have obstructive emphysema on chest x-ray. Further investigations found a mediastinal mass compressing the carina and left mainstem bronchus. The mass was excised and found to be of tuberculous origin., (Copyright 2003, Elsevier Science (USA). All rights reserved.)

Tissue replacement traditionally requires use of autologous tissue and is associated with the attendant morbidity of donor site harvest. In the case of allograft transplantation, there are concerns, similar to those associated with organ transplantation, of rejection and immunosuppression. For these reasons, emphasis has been placed on the development of tissue-engineered substitutes that incorporate autologous stem cells into tissue-engineered scaffolds. The authors' laboratory has characterized a population of cells obtained from processed lipoaspirate (PLA), which have the capacity in vitro to differentiate into osteoblasts, chondrocytes, myocytes, adipocytes, and neuron-like cells. Adipose tissue is an abundant, expendable, and easily obtained tissue that may prove to be an ideal source of autologous stem cells for engineering tissues.

We have characterized a population of mesenchymal progenitor cells from adipose tissue, termed processed lipoaspirate (PLA) cells, which have multilineage potential similar to bone marrow-derived mesenchymal stem cells and are also easily expanded in culture. The primary benefit of using adipose tissue as a source of multilineage progenitor cells is its relative abundance and ease of procurement. We examined the infection of PLA cells with adenoviral, oncoretroviral, and lentiviral vectors. We demonstrate that PLA cells can be transduced with lentiviral vectors at high efficiency. PLA cells maintain transgene expression after differentiation into adipogenic and osteogenic lineages after lentiviral transduction. Therefore, PLA cells and lentiviral vectors may be an efficient combination for use as a therapeutic gene delivery vehicle.

Our laboratory has recently characterized a population of cells from adipose tissue, termed processed lipoaspirate (PLA) cells, which have multi-lineage potential similar to bone-marrow-derived mesenchymal stem cells (MSCs). This study is the first comparison of PLA cells and MSCs isolated from the same patient. No significant differences were observed for yield of adherent stromal cells, growth kinetics, cell senescence, multi-lineage differentiation capacity, and gene transduction efficiency. Adipose tissue is an abundant and easily procured source of PLA cells, which have a potential like MSCs for use in tissue-engineering applications and as gene delivery vehicles., (Copyright 2003 S. Karger AG, Basel)

A paucity of information is available regarding the surgical repair of recurrent pectus deformities (RPD). From 1993 through 2001 35 patients ranging in age from 6 to 51 years (mean, 23 years) underwent repair of RPD a mean of 11 years after the original repair: modified Ravitch repair (31), prosthetic implantation (three), and Nuss procedure (one). All patients had accompanying symptoms including decreased stamina (76%), chest discomfort (53%), asthma (33%). The repair performed was dependent on the findings at operation. A modified Ravitch procedure with Adkins strut was performed for 21 patients. Three had reattachment of mobile costal cartilages and/or xiphoid process to the sternum; three patients had autologous bone or cartilage grafts, three had muscular reconstruction, and two had resection of a localized cartilage protrusion. Three patients could not be reconstructed safely. Very good to excellent results were achieved for 32 patients (mean follow-up, 24.8 months). There were no deaths or major complications. Minor complications occurred in five patients. The mean blood loss was 105 mL. The mean hospital stay was 2.8 days. We conclude that although it is technically difficult RPD can be repaired with low morbidity, short hospital stay, and very good physiologic and cosmetic results.

Much of the work conducted on adult stem cells has focused on mesenchymal stem cells (MSCs) found within the bone marrow stroma. Adipose tissue, like bone marrow, is derived from the embryonic mesenchyme and contains a stroma that is easily isolated. Preliminary studies have recently identified a putative stem cell population within the adipose stromal compartment. This cell population, termed processed lipoaspirate (PLA) cells, can be isolated from human lipoaspirates and, like MSCs, differentiate toward the osteogenic, adipogenic, myogenic, and chondrogenic lineages. To confirm whether adipose tissue contains stem cells, the PLA population and multiple clonal isolates were analyzed using several molecular and biochemical approaches. PLA cells expressed multiple CD marker antigens similar to those observed on MSCs. Mesodermal lineage induction of PLA cells and clones resulted in the expression of multiple lineage-specific genes and proteins. Furthermore, biochemical analysis also confirmed lineage-specific activity. In addition to mesodermal capacity, PLA cells and clones differentiated into putative neurogenic cells, exhibiting a neuronal-like morphology and expressing several proteins consistent with the neuronal phenotype. Finally, PLA cells exhibited unique characteristics distinct from those seen in MSCs, including differences in CD marker profile and gene expression.

Conjoined twins occur in approximately one of every 50,000 to 200,000 births. Atypical or parasitic conjoined twins result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Omphalopagus refers to conjoined twins joined at the level of the umbilicus. The authors report a case of atypical omphalopagus involving an acardiac, acephalic, parasitic twin and a host twin with a large omphalocele, transposition of the great arteries, and aortic coarctation. The authors briefly review reported cases of parasitic omphalopagus and emphasize the role of intensive neonatal care, preoperative planning, and staged surgical intervention in the successful management of complicated variants., (Copyright 2002, Elsevier Science (USA). All rights reserved.)

Chronic wounds are associated with considerable morbidity and prolonged hospitalizations. The availability of recombinant growth factors and cytokines provides a new modality for treatment of recalcitrant wounds. Granulocyte-macrophage colony-stimulating factor (GM-CSF), a growth protein for hematopietic cells, also enhances neutrophil and monocyte function and promotes keratinocyte proliferation. In three patients with inherited disorders associated with leukocyte dysfunction and non-healing wounds, topical application of GM-CSF resulted in complete wound closure within 1 to 4 weeks. A subcutaneous (s.c.) infusion pump for the local s.c. delivery of GM-CSF was also found to enhance healing. Local application of GM-CSF may thus promote wound closure in patients with impaired wound healing.

Learning Objectives: The reader is presumed to have a broad understanding of plastic surgical procedures and concepts. After studying this article, the participant should be able to: Physicians may earn 1 hour of Category 1 CME credit by successfully completing the examination based on material covered in this article. The examination begins on page ***., Background: The rapid development of disciplines such as cell therapy and tissue engineering has focused attention on stem cells as the ideal cellular substrate for new tissues. Human adipose tissue is a potential source of such stem cells., Objective: We review the role of human adipose tissue in stem cell research and describe the procurement of stem cells from the stromal vascular fraction of human adipose tissue obtained through suction-assisted lipoplasty., Methods: Raw lipoaspirate obtained through suction-assisted lipoplasty was washed in phosphate-buffered saline and digested with collagenase. The collagenase was then inactivated by fetal bovine serum and the cells were centrifuged for 10 minutes at 1200 x g. The resulting cell pellet was resuspended, plated, and maintained in nondifferentiating control media., Results: Processing of 250 to 500 mL of suctioned tissue routinely yielded 2 to 6 x 10(8) processed lipoaspirate cells. Cell viability was typically >95%. These cells have been shown to differentiate in vitro into at least the adipogenic, chondrogenic, myogenic, neurogenic, and osteogenic lineages in the presence of specific induction factors., Conclusions: Adipose tissue may be an ideal source of stem cells, because it is abundant, easy to obtain in large quantities, and safe to procure. Such a development could place the plastic surgeon at the epicenter of medical research. Issues that require further research include elucidation of site-specific differences in fat cells, the use of vacuum-assisted lipoplasty and ultrasound-assisted lipoplasty in procuring stem cells, and the development of more efficient and convenient tissue processing techniques. (Aesthetic Surg J 2002;22:121-127.).