Tissue engineering essentially refers to technology for growing new human tissue and is distinct from regenerative medicine. Currently, pieces of skin are already being fabricated for clinical use and many other tissue types may be fabricated in the future. Tissue engineering was first defined in 1987 by the United States National Science Foundation which critically discussed the future targets of bioengineering research and its consequences. The principles of tissue engineering are to initiate cell cultures in vitro, grow them on scaffolds in situ and transplant the composite into a recipient in vivo. From the beginning, scaffolds have been necessary in tissue engineering applications. Regardless, the latest technology has redirected established approaches by omitting scaffolds. Currently, scientists from diverse research institutes are engineering skin without scaffolds. Due to their advantageous properties, stem cells have robustly transformed the tissue engineering field as part of an engineered bilayered skin substitute that will later be discussed in detail. Additionally, utilizing biomaterials or skin replacement products in skin tissue engineering as strategy to successfully direct cell proliferation and differentiation as well as to optimize the safety of handling during grafting is beneficial. This approach has also led to the cells' application in developing the novel skin substitute that will be briefly explained in this review.
Biopolymer chitosan (beta-1,4-d-glucosamine) comprises the copolymer mixture of N-acetylglucosamine and glucosamine. The natural biocompatibility and biodegradability of chitosan have recently highlighted its potential use for applications in wound management. Chemical and physical modifications of chitosan influence its biocompatibility and biodegradability, but it is unknown as to what degree. Hence, the biocompatibility of the chitosan porous skin regenerating templates (PSRT 82, 87 and 108) was determined using an in vitro toxicology model at the cellular and molecular level on primary normal human epidermal keratinocytes (pNHEK). Cytocompatibility was accessed by using a 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl tetrazolium bromide (MTT) assay from 24 to 72h. To assess the genotoxicity of the PSRTs, DNA damage to the pNHEK was evaluated by using the Comet assay following direct contact with the various PSRTs. Furthermore, the skin pro-inflammatory cytokines TNF-alpha and IL-8 were examined to evaluate the tendency of the PSRTs to provoke inflammatory responses. All PSRTs were found to be cytocompatible, but only PSRT 108 was capable of stimulating cell proliferation. While all of the PSRTs showed some DNA damage, PSRT 108 showed the least DNA damage followed by PSRT 87 and 82. PSRT 87 and 82 induced a higher secretion of TNF-alpha and IL-8 in the pNHEK cultures than did PSRT 108. Hence, based on our experiments, PSRT 108 is the most biocompatible wound dressing of the three tested.
Von Willebrand disease (vWD) is the second least common hemostatic disorder in Malaysia, and it has a low prevalence. This study examined the underlying platelet thrombogenicity cascades in the presence of different formulations of chitosan-derivatives in vWD patients. This paper aimed to determine the significant influence of chitosan biomaterial in stimulating the platelet thrombogenicity cascades that involve the von Willebrand factor, Factor 8, Thromboxane A2, P2Y12 and Glycoprotein IIb/IIIa in vWD.
Hemipelvectomy is a major surgical procedure that associates with significant morbidity, functional impairment, and psychological and body image problem. Reconstruction of the defect is a challenged since a large amount of composite tissues are needed. We would like to share our eight-year experience with massive pelvic resection and reconstruction.
Increasing numbers of doctors are experiencing burnout now more than ever before and the worrying part is that what we see is just the tip of the iceberg. Burnout, a state of mental exhaustion caused by the doctor's professional life, is characterised by emotional exhaustion, depersonalisation and a reduced sense of accomplishment or success. Burnout has been largely ignored or under-recognised previously. This paper provides a perspective on burnout among doctors, including an overview of symptoms, the scale of the problem, the implications and causes of burnout and, finally, a strategic framework to provide a basis for managing it. Most importantly, professional bodies are urged to start taking steps to help troubled doctors. Medical Colleges should provide essential assistance, support and guidance as well as ensuring fair management and promotion policies.
We present a series of four cases of chest wall tumor, which underwent sternum resection. The methods of resection and reconstruction chest wall defect are discussed and the final outcome highlighted.
Basic fibroblast growth factor (bFGF) is angiogenic and effective in down-regulating excess collagen production. The aim of this study is to evaluate the effectiveness of vitamin E (Tocotrienol Rich Fraction) in altering the level of bFGF, a cytokine involved in the scar formation process. In this model, normal human fibroblasts were treated with various concentrations of vitamin E at different time frames. The levels of bFGF were determined by Enzyme-Linked Immunosorbant Assay (ELISA). This study demonstrated that Tocotrienol Rich Fraction (TRF) stimulated bFGF production by fibroblast and postulate that vitamin E may decrease aberrant scar formation.
Hemangiomas are the most common congenital lesions in man and occur predominantly in the head and neck region. Massive hemangioma especially near vital organs or structures pose a challenge to surgeons. With the availability of expertise in embolization of feeding vessel of the hemangioma and reconstructive techniques we were able to manage successfully a complicated case of massive facial hemangioma.
We present our two year experience with a dermal regeneration template (INTEGRA) in burn reconstructive surgery for contracture release as well as a reconstructive tool for management of soft tissue loss.
Osteosarcoma is a rare tumour in the sinonasal region. Early diagnosis is essential for adequate management and better prognosis and this requires a meticulous histopathological examination. Reported is a case of osteosarcoma misdiagnosed as chondrosarcoma and treated by surgery followed by radiotherapy. However, appropriate diagnosis and pre-operative chemotherapy would have been significant in the prognosis. The pitfall of accurate diagnosis and the subsequent treatment is discussed in order to find the ways to maximize five years survival which is not more than 25% in this type of lesions.
The treatment of major burn injuries are a formidable challenge to the burn surgeon. Early aggressive surgery for deep to full thickness burn injuries is vital in the prevention of infection. The ultimate goal in major burn injuries is to prevent the onset of multi-resistant organisms and achieve early wound cover. The field of tissue engineering can help to expedite the healing of these burn wounds. The development of keratinocyte culture delivery system can be used clinically to fasten the healing process and save many lives.
Vaginal defects can either be congenital or acquired due to tumor or trauma. The reconstructions are aimed in producing a good physical and functional result with the least donor site morbidity. The pudendal thigh flap is a sensate fasciocutaneous flap based on the terminal branch of the superficial perineal artery, the continuation of the internal pudendal artery. Although various flaps have been described for vaginal reconstruction, the pudendal thigh flap offers a very attractive alternative.
Total femur endoprothesis is an alternative replacement for massive malignant bone tumor with intramedullary extension or skip lesion. Four patients underwent total femoral resection and replacement with megaprosthesis: three had primary malignant bone tumor and one had salvage procedure for aseptic loosening of the distal femoral replacement. Tumor-free margins were achieved in all patients with two patients required vascularized latissimus dorsi free flap cover for reconstruction of soft tissue defects. The average follow-up was 24 months (range 16 - 60 months). All four patients were still alive with three of them being disease-free and one survived even with the presence of lung metastasis. The functional results obtained were either excellent or good in all patients in accordance to the Musculoskeletal Tumors Society grading system.
Post-traumatic chronic osteomyelitis and infected non-unions of the tibia following severe type-III open fracture are difficult to treat Refractoy cases often necessitate amputation despite attempts to salvage the limb. We report our experience in treating such difficult cases with an alternative surgical option using free osteocutaneous fibular graft. Eight consecutive patients with post-traumatic chronic osteomyelitis/infected non-union were treated surgically with free vascularized osteocutaneous fibular graft. Outcomes in term of graft-host union and complication were evaluated. Four patients had anastomotic venous thrombosis requiring anastomotic revision. Five patients developed surgical site infections needing extended antibiotic therapy to achieve resolution at an average of 15.2 weeks. Fibular graft fracture occurred in three patients but all grafts survived and united after a mean time to union of 42.3 weeks (range 31 to 82 weeks). At the final follow-up, union of host-graft junction and control of infection were achieved in all patients except one who required a secondary amputation. Free vascularized osteo-cutaneous fibular graft is a viable limb salvage option for refractory chronic osteomyelitis or infected non-union following treatment of grade-III open tibial fractures.
The use of 'spare part' tissue from an amputated segment to cover a stump with soft tissue deficiency is a viable option for augmenting the shape of the stump and preserving functional length of the stump without additional donor morbidity. The procedure requires no microsurgical skill if the tissues are used as pedicle fillet flaps transfer. This concept of fillet flap makes the amputation distal to an unfavourable definitive amputation site such as in congenital constriction band possible. We report herein a case of amputation distal to constriction ring to illustrate the application of fillet flap in reconstruction surgery.
A rectus abdominis myocutaneous flap can provide a large amount of tissue for defect coverage. Rarely a flabby and redundant abdominal tissue was used as a huge extended flap. We report a case of recurrence malignant fibrous histiocytoma of the thigh which was radically resected. The resultant massive defect was success reconstructed with an extended pedicle inferiorly based rectus abdominis myocutaneous flap.
We reviewed the surgical and oncological management 23 consecutive patients with osteosarcoma of the long bones to determine the outcome of limb salvage technique performed in our centre. All patients received neoadjuvant chemotherapy. There were 15 males and 8 females with a mean age at diagnosis of 19 years (9 to 36). The median follow-up was 30 months (10 to 60). Fifteen had lesion around the knee joint followed by three in the proximal humerus, two in distal humerus, two in the pelvis, and one in the distal tibia. Six patients presented with lung metastases at diagnosis. We performed limb salvage surgery to control local disease in 16 patients and amputation in 7. The resection margins of the primary lesion were adequate and free of tumour cells in all patients. Local recurrence developed in 1 patient of limb salvage group. The overall median survival was 22 months and actuarial survival was 52% at 3 years. Eleven patients died of pulmonary metastases within 2 years of follow-up. Median survival of the limb salvage surgery group was 30 months compared to 6 months in the amputation group. As per our experience, limb salvage technique is a feasible option in extremity osteosarcoma without compromising survival.
Long bone reconstruction using vascularized fibula graft is becoming more popular despite the difficulties and its post-operative complications. We reviewed our early experience dealing with vascularized fibula graft for the management of massive long bone defect. Thirteen patients had undergone long bone reconstruction using vascularized fibula graft. Early complications that had been encountered include superficial wound infection (23%), transient common peroneal nerve palsy (23%), stage 1 bed sore (7.7%), anastomotic venous thrombosis (30.8%), DIVC (15.4%), flap loss and amputation (7.7%), and reactive psychiatric problem (7.7%). The early complications following this procedure are comparable with other major orthopaedic surgery and most of them are minor and treatable. The complication rates are also comparable with similar surgery done elsewhere.
Reconstructive surgeons often encounter complex soft tissue and skeletal defects following oncological surgery. Soft tissue defects after wide resection in upper extremities posses a difficult challenge to find adequate tissue for reconstructing these defects. Paucity of local tissues dictates the requirement of loco-regional or distant flaps for these complex soft tissue defects which often exposes tendons, bones, nerves and joints. The latissimus dorsi muscle is a near ideal flap for the reconstruction because of the long neurovascular pedicle, ease of mobilization and its expendability. It can be rotated, with or without overlying skin, to cover soft tissue defects of the shoulder arm and elbow. Due to the large size of the muscle, it can be used to resurface the soft tissue defects and cover all major structures. Eleven consecutive cases were reviewed in which latissimus dorsi myocutaneous flap was used to reconstruct soft tissue defects of the upper limb following radical tumor resection. Flap survival was 100% with nominal donor site morbidity.
Partial scalp alopecia is a common problem that can lead to severe social and psychological problems. Tissue expansion, although an old concept, provides a surgical alternative to manage areas of alopecia. We describe a case of alopecia secondary to repaired occipital encephalocele that was successfully treated using tissue expansion technique.