Nerve conduits for peripheral nerve surgery.

Autologous nerve grafts are the current criterion standard for repair of peripheral nerve injuries when the transected nerve ends are not amenable to primary end-to-end tensionless neurorrhaphy. However, donor-site morbidities such as neuroma formation and permanent loss of function have led to tremendous interest in developing an alternative to this technique. Artificial nerve conduits have therefore emerged as an alternative to autologous nerve grafting for the repair of short peripheral nerve defects of less than 30 mm; however, they do not yet surpass autologous nerve grafts clinically. A thorough understanding of the complex biological reactions that take place during peripheral nerve regeneration will allow researchers to develop a nerve conduit with physical and biological properties similar to those of an autologous nerve graft that supports regeneration over long nerve gaps and in large-diameter nerves. In this article, the authors assess the currently available nerve conduits, summarize research in the field of developing these conduits, and establish areas within this field in which further research would prove most beneficial.

Rupture of all digital flexors following Colles' fracture.

Flexor tendon rupture following a Colles' fracture is a rare complication with only a handful of cases reported since the initial report in 1932. We present a case in which all digital flexor tendons ruptured within 6 months of a Colles' fracture. Previous reported cases have demonstrated rupture of either the radial or ulnar digital flexors but this case is the first in which all the digital flexors have been involved. This case report highlights the clinical implications of this rare occurrence and stresses the importance of accurate reduction and thorough clinical examination following bony injuries to the wrist.

A well vascularised muscle flap--drug user's dream.

It is estimated that worldwide, 16 million people, aged 15-64 years inject illicit drugs regularly. When peripheral venous access becomes obliterated, drug users start injecting into the subdermal area of the skin - "skin popping". When this area ulcerates, the well vascularised granulation tissue called a "shooter's patch" is maintained as a portal for continuing injection. These "shooter's patches" are usually on the limbs, but have been reported on the breast and the penis. We present a case of a reconstructive muscle flap being used in an unforeseen manner as a shooters patch. Surgeons rely on muscle flaps to provide a robust reconstructive option, but we have learnt that drug users value them for their rich vascularity and high absorption.

Recent advances in artificial nerve conduit design: strategies for the delivery of luminal fillers.

Artificial nerve conduits offer an attractive alternative to nerve autografts for the repair of peripheral nerve injuries and several commercially-available conduits are currently on the market. However, at present, utilization of these conduits is limited to the repair of nerve gaps less than 3 cm in length. Thus, current research is focused on how best to design artificial conduits with improved nerve regeneration potential over longer distances. Successful nerve regeneration necessitates that the cells, extracellular matrix components, and growth factors involved interact in a highly specific manner that is tightly coordinated. Combinatorial approaches that take into account these interactions and conduits that utilize supportive factors, such as neurotrophins and stem cells, may be key components of the next generation of artificial conduits. Additionally, design strategies that combine physical cues for contact guidance and biochemical signals to enhance cellular function have shown promise. This review highlights recent advances in artificial nerve conduit design, focusing on the use of luminal fillers, with special focus on the various techniques for accessory cell and/or growth factor delivery into artificial nerve conduits.

Swiss roll technique for treatment of paronychia.

Management of paronychia should primarily be aimed at preventing any activity that results in impairment of the natural barrier function of the nail fold. Surgical treatments aim to cure paronychia by exposing the inflamed germinal matrix to permit unrestricted drainage. We describe a Swiss roll technique for treatment of chronic and severe acute paronychia.

Refinement of a simple technique with new relevance for exsanguination of the upper limb.

Many techniques have been described for exsanguination of the upper limb before the application of a pneumatic tourniquet. These require additional equipment such as the Esmarch bandage, the Urias bag, the Pomidor roll-cuff, the Northwick Park exsanguinator, or the Rhys-Davies exsanguinator. At a time of increasing demand on scarce resources and increasing medico-legal claims, these techniques have a number of disadvantages: increasing tourniquet and theater time, having cost implications, posing a risk of transmission of infection such as methicillin-resistant Staphylococcus aureus and Group A Streptococcus, being contraindicated in certain upper limb pathologies, and causing potential injury or even fatal pulmonary embolism. Some of these techniques continue to be in common usage but a review of the literature suggests that they may be unnecessary in routine practice, and should be reserved for select situations. The present article describes the formalization and refinement of a simple technique with new relevance, 101 years after Bier first mentioned it in the literature, where the brachial artery is compressed in the cubital fossa before elevation of the arm and then the tourniquet is inflated. This method is simple, cost-effective, time-saving, and most importantly safe and fomite free.

Growth Factors and their receptors in cancer metastases.

Metastatic, rather than primary tumours are responsible for ninety percent cancer deaths. Despite significant advances in the understanding of molecular and cellular mechanisms in tumour metastases, there are limitations in preventive treatment of metastatic tumours. Much evidence arising from laboratory and clinical studies suggests that growth factors and their receptors are implicated in cancer metastases development. We review the origin and production of growth factors and their receptors in all stages of cancer metastases including epithelial-mesenchymal transition, cancer cell invasion and migration, survival within the circulation, seeding at distant organs and metastatic tumour angiogenesis. The functions of growth factors and their receptors are also discussed. This review presents the efforts made in understanding this challenge to aid in the development of new treatment strategies for cancer metastases.