Technology insight: telementoring and telesurgery in urology

The rapid expansion of the field of minimally invasive surgery has been accompanied by a number of controversies. These novel surgical techniques offer benefits to the patient with regard to length of hospital stay, return to full activity, and cosmesis; also, they are often more cost-effective than open procedures. On the other hand, they are technically demanding, have a significant learning curve, and can be associated with high initial complication rates unless performed by experienced endoscopic surgeons. Telemedicine, which uses real-time video and information transfer, offers the potential to increase the availability of minimally invasive surgery through video-assisted surgery and through remote instruction. At present, remote communities, especially those within developed countries, can most immediately benefit from telesurgical approaches. Enthusiasm must be tempered by the issues of cost, security, surgeon liability and availability of the technology itself which have yet to be fully resolved. In this Review, the field of telemedicine, focusing specifically on telementoring and telesurgery, and its relevance to urology are discussed. From early experimental work to current clinical usage, the advantages of and problems in this evolving field are explored.     

Tissue engineering: in vitro creation of tissue substitutes

Tissue engineering is a young, multidisciplinary scientific field which aims at generating bioartificial tissues in vitro to restore diseased human organs. This fledgling sector of biosciences emerged few years ago but draws scientific and public attention increasingly, as the recent accomplishments are impressive and promise alternative therapeutic concepts to replace or enhance failing human organs. Tissue engineering using either polymers or decellularized native allogeneic or xenogeneic matrices may provide the techniques to develop the ideal graft. The matrix scaffold can be seeded with cells that organise and develop into tissue prior to or following implantation. This review surveys upon recent developments in the field of in vitro tissue engineering (skin, heart, heart valves, blood vessels, liver, kidney, urogenital, and nerves), without claiming completeness, thus providing an insight into what has been attempted and what may be possible in the near future.     

Tissue engineering in urology

Congenital abnormalities, cancer, trauma, infection, inflammation, iatrogenic injuries, and other conditions may lead to genitourinary organ damage or loss, requiring eventual reconstruction. Tissue engineering follows the principles of cell transplantation, materials science, and engineering toward the development of biological substitutes that would restore and maintain normal function. Tissue engineering may involve matrices alone, wherein the body’s natural ability to regenerate is used to orient or direct new tissue growth, or the use of matrices with cells. Both synthetic (polyglycolic acid polymer scaffolds alone and with co-polymers of poly-1-lactic acid and poly-DL-lactide-coglycolide) and natural biodegradable materials (processed collagen derived from allogeneic donor bladder submucosa and intestinal submucosa) have been used, either alone or as cell delivery vehicles. Tissue engineering has been applied experimentally for the reconstitution of several urologic tissues and organs, including bladder, ureter, urethra, kidney, testis, and genitalia. Fetal applications have also been explored. Recently, several tissue engineering technologies have been used clinically, including the use of cells as bulking agents for the treatment of vesicoureteral reflux and incontinence, urethral replacement, and bladder reconstruction. Recent progress suggests that engineered urologic tissues may have clinical applicability in the future.     

Tissue engineering in urology

Techniques that are aimed at regeneration of human tissues and organs (tissue engineering) have recently entered into clinical practice. Tissue engineering is currently among the fastest growing areas in medicine, and involves the application of the principles of biology and engineering to the development of functional substitutes for damaged tissues. One of the main limitations of reconstructive surgery in the genitourinary tract is the lack of autologous tissue. This could be changed by the ability to cultivate the patient's own tissues in vitro, or by stimulating the cells in vivo into regeneration of new tissues. The present review discusses how tissue engineering can be used to regenerate some of the tissues of the genitourinary tract. Even though these methods have only recently been introduced clinically into genitourinary medicine, numerous scientific studies have been reported that indicate that these techniques may be of great importance in the near future.     

Current status of tissue engineering in urology. Review of the literature

In the eighties a new field of the medicine appears wich applies the principles of cellular cultivation to synthetic biodegradable polymers scaffolds with the purpose of creating autologous biological substitutes that could improve, maintain or restore the function of organs or damaged tissues. The Tissue Engineering constitutes a new discipline in full phase of development especially in USA, with multiple potential applications in several medical specialities. Our speciality can't remain indifferent to interest and encouraging future originated by this new science. In this work we have made a wide bibliographical revision in the Medline to know the antecedents, current state and the possible future applications of Tissue Engineering in Urology.     

Tissue engineering in urology

Tissue engineering refers to the techniques that are aimed at regeneration of human tissues and organs. Two elements are necessary for these techniques: matrix and cells. Matrix is the scaffold where tissues may organise. Cells are either autologous cells stimulated to regenerate in vivo, aided by implantation of matrix ("guided tissue regeneration"), or autologous cells cultured outside the body (in vitro) and later returned as auto-transplants. All types of conventional tissue reconstructive surgery need tissue engineering. These techniques have been introduced recently into the clinical practice. One of the main limitations of reconstructive surgery in genitourinary tract is the lack of autologous tissue. Two autotransplants could be distinguished: coherent tissue structure or cell suspensions. The great number of studies published in this area emphasizes the importance of the future clinical implication in urology.     

Tissue engineering in urology

Tissue engineering encompasses a multidisciplinary approach geared toward the development of biological substitutes designed to restore and maintain normal function in diseased or injured tissues. This article reviews the basic technology that is used to generate implantable tissue-engineered grafts in vitro that will exhibit characteristics in vivo consistent with the physiology and function of the equivalent healthy tissue. We also examine the current trends in tissue engineering designed to tailor scaffold construction, promote angiogenesis and identify an optimal seeded cell source. Finally, we describe several currently applied therapeutic modalities that use a tissue-engineered construct. While notable progress has clearly been demonstrated in this emerging field, these efforts have not yet translated into widespread clinical applicability. With continued development and innovation, there is optimism that the tremendous potential of this field will be realized.     

Applications of microsurgery in urology

The applications of microsurgery in urology have increased in the decade since urologists first used such techniques. The primary uses for microsurgery in urology at first were vasovasostomy, vasoepididymostomy, and testicular autotransplantation. Penile revascularization has recently become another procedure for which microsurgery is used with increasing frequency. As more urologists learn the techniques, other urologic applications for microsurgery surely will develop.     

应用负载碱性成纤维细胞生长因子的人脱细胞羊膜构建人工活性真皮

目的 探讨构建一种新型人工活性真皮的可行性.方法 组织块法培养幼儿包皮成纤维细胞;采用酶-去垢剂法制备人脱细胞羊膜(HAAM);双相法制备碱性成纤维细胞生长因子(bFGF)-明胶-壳聚糖缓释微球;缓释微球黏附于HAAM;bFGF基体式负载于HAAM,绘制药物缓释曲线;将第3～4代成纤维细胞培养于负载缓释微球的HAAM;扫描电镜观察HAAM、缓释微球的表面特征及缓释微球与HAAM的粘附情况;Western印迹法检测成纤维细胞中层粘连蛋白的表达.结果 制备的HAAM为白色半透明状薄膜,有较高的孔隙率,空隙不规则,孔径大小为10～100 nm,无细胞毒性;bFGF-明胶壳聚糖缓释微球分散较均匀,呈球形,粒径均匀,球体表面比较光滑,载药率为20 ng/g,包封率为80.5％,体外药物缓释曲线显示药物控释效果良好;成纤维细胞在支架表面爬行生长良好,层粘连蛋白表达较对照组高.结论 通过将成纤维细胞种植于负载bFGF-明胶-壳聚糖缓释微球的HAAM,有望制备出一种新型的人工活性真皮.     

组织工程化椎间盘构建及其生物学评定

目的 探讨人骨髓间充质干细胞(BM-MSCs)经诱导转化为人髓核细胞(NPs)并构建组织工程椎间盘的价值.方法 体外培养胎儿NPs及BM-MSCs并种植在聚乳酸-聚羟基乙酸共聚物(PLGA)支架上,倒置显微镜及扫描电镜进行形态学观察.将载有BM-MSCs和NPs的PLGA支架及BM-MSCs和NPs的细胞悬液植入新西兰大白兔椎间盘中,12周后对椎间盘信号强度按Thompson分级进行评定.分光光度法检测蛋白聚糖并免疫组化检测Ⅱ型胶原的表达.结果 BM-MSCs在与NPs共培养后由梭形、多角形变为成纤维细胞样,且两种细胞在PLGA支架表面贴附,形态正常,生长良好;载有BM-MSCs和NPs的PLGA支架在椎间MRI信号维持、蛋白多糖[PLGA支架组含量为(3.93±0.31)mg/100 mg,对照组为(3.52±0.26)mg/100 mg]及Ⅱ型胶原表达上较对照组差异均有统计学意义(P＜0.05).结论 共培养可促使BM-MSCs向NPs转化,PLGA支架为细胞提供良好的生长环境,其力学性能维持和空间结构保障可以满足BM-MSCs与NPs构建组织工程椎间盘的需要,有效延缓了椎间盘的退变.

Abstract：

Objective To investigate the value of bone marrow-mesenchymal stem cells(BMMSCs)transformed by nucleus pulposus(NPs)for construction of tissue engineering disc.Methods BMMSCs and fetal NPs were cultured in vitro,planted on polylactic acid-polyglycolic acid copolymer(PLGA),and observed with inverted microscope and scanning electronic microscope.PLGA scaffolds with adherent BM-MSCs and NPs,as well as BM-MSCs and NPs suspension were implanted into intervertebral discs of New Zealand white rabbits,respectively.Intervertebral signal intensity was evaluated by Thompson grading 12 weeks later.Proteoglycan and type Ⅱ collagen were determined by spectrophotometric method and immunohistochemistry,respectively.Results Spindle or multi-angular BM-MSCs turned into fibro-like phenotype coculture of BM-MSCs and NPs,which grew well with normal morphology when they attached on PLGA scaffolds.There was statistical difference in intervertebral signal intensity,and the expression of proteoglycan and type Ⅱ collagen between PLGA scaffolds group and control group(P＜0.05),the content of proteoglycan was(3.93 ± 0.31)mg/100 mg in the PLGA scaffolds group whereas(3.52 ± 0.26)mg/100 mg in the control group.Conclusions BM-MSCs can be induced into NPs by cocultivation,and PLGA scaffolds can provide good growing conditions,and maintain high mechanical properties and spacial structure which meet the requirement of tissue engineering disc to prevent degeneration.     

全生物化组织工程血管的体外构建

目的 探讨组织工程血管的体外构建:脱细胞血管基质的制备.血管平滑肌细胞和血管内皮祖细胞的体外诱导培养和种植方法.方法 处理猪胸主动脉来获得脱细胞血管基质,采用二步种植法先后种植体外培养的平滑肌细胞和内皮细胞.结果 动脉管壁细胞全部脱除,脱细胞基质胶原蛋白含量与新鲜动脉相似,胶原纤维、弹性纤维呈网状排列,无断裂,基质保持完好.脱细胞血管基质的极限应力比新鲜动脉绀织减小20%[新鲜动脉:(1.1510±1.2870)×10-2,脱细胞血管基质:(0.9215±1.7000)×10-2,t=34.137,P<0.01].种植的平滑肌细胞和内皮细胞生长良好.结论 平滑肌细胞和内皮细胞种植于脱细胞血管基质后生长良好,可体外构建组织工程血管.