External oblique intercostal (EOI) block for enhanced recovery after liver surgery: a case series.

We report our clinical experience with the external oblique intercostal block in three consecutive adult patients who underwent liver surgery for resection of metastases. Enhanced recovery guidelines for liver surgery recommend intrathecal opioids and peripheral regional anaesthetic techniques in the context of multimodal analgesia to achieve adequate postoperative analgesia and early functional recovery. However, both laparoscopic and open approaches to liver surgery involve incisions in the upper abdomen, an anatomical area not well covered by previously described peripheral regional anaesthetic techniques. The external oblique intercostal block is a novel motor- and opioid-sparing technique which blocks both the anterior and lateral cutaneous branches of the thoracoabdominal nerves which innervate the upper abdominal quadrant. In all cases in this series, we performed the blocks in a short period of time and without complications. All patients remained pain- and opioid-free in the postoperative period and achieved enhanced recovery outcomes early. We found the external oblique intercostal block to be a simple, convenient, effective and opioid-sparing regional anaesthetic technique for postoperative analgesia after liver surgery. By minimising opioid use and by obviating the need for central neuraxial anaesthesia techniques in the postoperative period, this block could be incorporated into enhanced recovery protocols for hepatobiliary surgery.

Gene transfer into human hematopoietic progenitor cells with an episomal vector carrying an S/MAR element.

Episomally maintained self-replicating systems present attractive alternative vehicles for gene therapy applications. Recent insights into the ability of chromosomal scaffold/matrix attachment regions (S/MARs) to mediate episomal maintenance of genetic elements allowed the development of a small circular episomal vector that functions independently of virally encoded proteins. In this study, we investigated the potential of this vector, pEPI-eGFP, to mediate gene transfer in hematopoietic progenitor cell lines and primary human cells. pEPI-eGFP was episomally maintained and conferred sustained eGFP expression even in nonselective conditions in the human cell line, K562, as well as in primary human fibroblast-like cells. In contrast, in the murine erythroleukemia cell line, MEL, transgene expression was silenced through histone deacetylation, despite the vector's episomal persistence. Hematopoietic semisolid cell colonies derived from transfected human cord blood CD34(+) cells expressed eGFP, albeit at low levels. After 4 weeks, the vector is retained in approximately 1% of progeny cells. Our results provide the first evidence that S/MAR-based plasmids can function as stable episomes in primary human cells, supporting long-term transgene expression. However, they do not display universal behavior in all cell types.

Genetic modification of hematopoietic stem cells with nonviral systems: past progress and future prospects.

Serious unwanted complications provoked by retroviral gene transfer into hematopoietic stem cells (HSCs) have recently raised the need for the development and assessment of alternative gene transfer vectors. Within this context, nonviral gene transfer systems are attracting increasing interest. Their main advantages include low cost, ease of handling and large-scale production, large packaging capacity and, most importantly, biosafety. While nonviral gene transfer into HSCs has been restricted in the past by poor transfection efficiency and transient maintenance, in recent years, biotechnological developments are converting nonviral transfer into a realistic approach for genetic modification of cells of hematopoietic origin. Herein we provide an overview of past accomplishments in the field of nonviral gene transfer into hematopoietic progenitor/stem cells and we point at future challenges. We argue that episomally maintained self-replicating vectors combined with physical methods of delivery show the greatest promise among nonviral gene transfer strategies for the treatment of disorders of the hematopoietic system.