不同聚丙烯网用于乳房下垂矫正的生物力学研究

目的 探讨4种不同的聚丙烯网片的生物力学性能,为真皮帽法乳房缩小术中内置式乳罩的选择提供依据.方法 以实验用小型猪作动物模型,将4种不同的聚丙烯网埋置于腹部皮下,90 d后采集标本,比较其生物力学性能.结果 4种聚丙烯网在拉伸强度、应力-应变关系、应力松弛和蠕变4个方面显示出不同的生物力学特性,这显然与它们所采用的材料和编织结构不同有关.结论 应力松弛和蠕变作为网片特殊的生物力学特性在维持术后乳房正常形态上有重要意义,在内置式乳罩的选择标准中占有重要的地位.Premilene Mesh LP~(R)作为新型的轻重量、小孔径网片,在生物力学性能上优于其他网片.     

应用聚丙烯单丝网片纠正轻、中度乳房下垂

目的：介绍一种适用于轻、中度乳房下垂的矫正术。方法：采用乳晕周围环状切口，用聚丙烯单丝网片制成内置式乳罩，行乳腺组织的上提、塑形和固定，并为21例乳房下垂者行矫正术。结果：21例均达到较为理想的上提效果，随访2－16个月，无下垂复发和切口瘢痕增生，未发生异物排斥反应。结论：聚丙烯单丝网片用作乳房塑形的支持材料安全可靠，减少了切口的瘢痕增生，避免了下垂复发。     

应用聚丙烯单丝网片纠正轻中度乳房下垂

目的　探讨一种外形美观、瘢痕最小、效果持久的乳房下垂矫正术的手术方法。方法　采用乳晕周围环状切口 ,用聚丙烯单丝网片制成内置式乳罩 ,行乳腺组织的上提、塑形和固定 ,为 2 1例乳房下垂病人行乳房下垂矫正术。结果　全部病人均达到较为理想的上提效果 ,随访 2个月～ 16个月 ,无继发下垂和切口瘢痕增生 ,未发生异物排斥反应。结论　聚丙烯单丝网片用作乳房塑形的支持材料是安全可靠的 ,减少了切口瘢痕增生的机会 ,避免了继发下垂的发生。     

乳房下垂矫正术中的乳房悬吊结构重建

目的总结用乳房悬吊结构重建方法矫正轻、中度乳房下垂的临床经验。方法通过乳晕边缘切口，去除上半腺体后松弛的浅筋膜深层，上提腺体至正常位置并固定于深筋膜，腺体浅面按真皮乳罩原理进行悬吊并适当切除乳晕周边多余皮肤，或采用聚丙烯单丝网片对腺体进行悬吊，术后腺体周围形成强大的纤维粘连，从而重建乳腺的悬吊支持结构。同时进行腺体的适当折叠塑形或置入乳房假体增加丰满程度。结果共行轻、中度下垂32例手术（其中单纯悬吊10例，悬吊同时假体隆乳20例，采用聚丙烯网片悬吊2例），手术时间90～150min，平均110min。术中出血量30～100ml，平均58ml。均未发生乳头乳晕坏死感觉障碍等并发症。术后随访6～12个月，平均11．3月，术后外形改善满意率90．6％（29／32）。结论对于不伴腺体肥大的乳房轻、中度下垂，采用乳房悬吊结构重建，是一种创伤相对小，安全，有效的矫正方法。     

乳房上提术中聚丙烯网片生物学特性观察研究

聚丙烯网片（以下简称网片）多用于巨大腹壁疝及腹股沟疝的修补,近年来乔群等将其用于乳房缩小整形术中的乳房上提术。为了解网片在人体内的变化，周围组织的反应，确定网片在乳房上提术中作用，我们在光学显微镜和扫描电子显微镜下，观察了网片本身的变化及其周围组织的结构情况。     

腹股沟疝无张力行聚丙烯网片修补196例观察

腹股沟疝是临床常见病,男性多于女性,严重影响了患者工作与生活.笔者根据聚丙烯生物材料在化学和生物学上较为稳定,组织相容性佳,其强度与柔软性佳,不易老化,极少出现异物反应的理化特性,采用0.3mm该材料网片,让腹股沟管前后壁纤维组织通过网孔生长,使腹横筋膜更易融合,从而达到修复腹股沟管的目的,且保持了原腹股沟管的解剖生理结构.腹股沟疝腹腔压力增高的病人,传统疝手术后张力大,通过聚丙烯网片对腹股沟疝修补术后张力的减压作用进行前瞻性疗效观察和研究.笔者自1995年2月至2003年8月,对腹股沟疝无张力行聚丙烯网片修补196例,获得满意疗效.现报告如下.     

两种补片修补TRAM皮瓣切取后腹壁缺损的临床效果比较

目的:比较聚丙烯网片与膨体聚四氟乙烯补片修补TRAM皮瓣切取后腹壁缺损的有效性及安全性。方法:回顾性分析85例游离TRAM皮瓣切取术后腹壁缺损的修补,比较两组患者术后并发症的发生率。结果:两组患者均无腹壁疝发生;聚丙烯网片组患者腹壁膨出率为6.3%,膨体聚四氟乙烯补片组为5.7%,无显著性差异;膨体聚四氟乙烯补片组术后感染率及积血积液率略高于聚丙烯网片组,无显著性差异;聚丙烯网片组患者术后疼痛不适及异物感发生率为34.4%,高于膨体聚四氟乙烯组的3.8%,差异具有统计学意义。结论:两种补片对于修复TRAM皮瓣切取后腹壁缺损都是有效的,膨体聚四氟乙烯补片更佳。     

聚丙烯单丝网片用于乳房下垂的矫正

目的 介绍一种矫正乳房下垂的新术式。方法 采用乳晕周围双环切口．并沿腺体表面向腺体边缘分离，然后置入聚丙烯单丝网片对松弛的乳腺组织上提、塑形、固定，对腺体组织较多者同时行楔形切除外上象限部分乳腺组织的乳房缩小术。结果 随访20例患者3～18个月，乳房下垂的矫正效果较理想，无下垂复发和切口瘢痕增生，未发现异物排斥反应。结论 聚丙烯单丝网片对于乳房下垂的矫正和塑形较安全可靠，能避免下垂的复发，减少了切口瘢痕的增生。     

不同类型网片对大鼠输精管组织结构影响的对比研究

目的研究探讨重量型聚丙烯网片、轻量型聚丙烯网片和聚酯网片在不同时期对大鼠输精管组织结构的影响。方法选取雄性成年SD大鼠60只,周龄(8.8±0.7)周,体重(286±75)g。采用随机数表法分成四组:对照组、重量型聚丙烯网片组(HWPP组)、轻量型聚丙烯网片组(LWPP组)、聚酯组各15只大鼠。对照组:仅分离单侧精索及周围血管后缝合切口;HWPP组、LWPP组、聚酯组:分离单侧精索及周围血管后用相应的网片包绕精索。各组分别在术后1、4、12周时处死5只大鼠,采集大鼠的输精管标本,通过分析输精管皱襞数量和固有膜与黏膜层紧密性来评估不同类型网片对精索组织结构的影响。结果 (1)术后各组输精管管腔无闭塞现象。(2)对照组输精管皱襞数量在术后1、4、12周时无明显变化(P0.05),而HWPP组、LWPP组、聚酯组的输精管皱襞数量在术后1、4、12周较对照组均且差异有统计学意义(P0.05),随网片在大鼠体内放置时间的延长输精管的皱襞数呈现进行性减少现象,其中HWPP组的输精管皱襞数量较LWPP组和聚酯组减少更为明显(P0.05),而LWPP组和聚酯组的皱襞数量差别比较无统计学意义(P0.05)。(3)术后1、4、12周时对照组输精管固有膜与黏膜层未见明显分离现象(P0.05);术后1周HWPP组、LWPP组、聚酯组输精管的固有膜与黏膜层分离现象较对照组没有明显差异(P0.05);在术后4周时HWPP组的固有膜与黏膜层分离现象较对照组明显增多(P0.05),而LWPP组、聚酯组较对照组无明显差异(P0.05);在术后12周时三个网片组的固有膜与黏膜层分离现象较对照组明显增多且差别均有统计学意义(P0.05),随网片在大鼠体内放置时间的延长HWPP组、LWPP组和聚酯组的输精管固有膜的分离现象都会增加,其中HWPP组的固有膜与黏膜层分离现象较LWPP组和聚酯组增加的更加明显,其差异有统计学意义(P0.05),而聚酯组和LWPP组相比无明显差异(P0.05)。结论三种网片对大鼠输精管的组织结构均存在不同程度影响,HWPP网片较LWPP和聚酯网片对输精管的影响较大,并且这种影响随着网片在大鼠体内植入时间的延长而增大。     

生物型补片与聚丙烯补片修补家猪腹壁缺损的对比研究

目的通过比较观察生物型补片与聚丙烯补片修补家猪腹壁缺损后的组织病理学变化，进一步探讨此生物型补片在疝修补治疗中应用的可行性。方法分别于10只小猪的腹直肌左右侧腹壁制成-6cm×4cm的肌肉腱膜层缺损区。左侧缺损区用生物型补片进行手术修补，右侧用聚丙烯补片修补。分别于修补术后1、3、6、12个月取材行大体观察及组织病理学检查。结果小猪在修补术后均未发生腹壁切口疝。术后1年内，聚丙烯侧的补片结构不能被吸收而始终存在，局部的炎症反应较明显；生物补片侧在各期的局部炎症反应轻于聚丙烯侧，且补片成分变性吸收，逐步由结缔组织所替代。结论生物型补片的组织相容性较好，能诱导组织再生，实现对缺损的再生性修复，有可能成为一种比较理想的疝修补材料。     

A single-surgeon randomized trial comparing three composite meshes on chronic pain after Lichtenstein hernia repair in local anesthesia

Background Chronic pain may be a long-term problem related to operative trauma and mesh material in Lichtenstein hernioplasty. Study design Inguinal hernioplasty was performed under local anesthesia in 228 patients (232 hernias) in day-case surgery by the same surgeon and exactly by the same surgical technique. The patients were randomized to receive either a partly absorbable polypropylene–polyglactin mesh (Vypro II^R 50 g/m², 79 hernias), a lightweight polypropylene mesh (Premilene Mesh LP^R 55 g/m², 75 hernias) or a conventional densely woven polypropylene mesh (Premilene^R 82 g/m², 78 hernias). Pain, patients discomfort and recurrences of hernias were carefully followed at days 1, 7, 1 month, 1 and 2 years after surgery. Results The duration of operation (29–33 min) and the amount of local anesthetic (55–57 ml) were similar in the three groups. Two wound infections and four hematomas were detected with no difference between the meshes. Immediate pain reaction up to 1 month was statistically equal among the three meshes. After 2 years of follow-up, there were five recurrences (two in the Vypro group, one in the Premilene LP and two in the Premilene). A feeling of a foreign body, sensation of pain and patient’s discomfort were similar with all meshes. Conclusion There was no difference of pain and quality of life among a conventional polypropylene mesh, lightweight mesh or partly absorbable mesh in 2 years of follow-up, when the same surgeon operated on all patients with exactly the same technique.     

Biological behavior of polypropylene meshes suitable for intra-abdominal implantation in animal model

The expected incisional hernia rate is between 11-20% after laparotomy. Using mesh repair the results of the hernioplasty have recently improved. However the complication of mesh implants--especially in intraperitoneal position--can be life threatening. Additionally the appropriate mesh is expensive. We tried to create a mesh, which can be used intraperitoneally and generates adhesion in the abdominal wall, but keeps the intraabdominal organs adhesion free. Our experiments were divided into four groups. In the first we used different materials to cover the intraperitoneal side of polypropylene mesh. In the second phase three different pore-sized meshes were compared. In the third part the biological behavior of three different material-reduced meshes were investigated. Based on our previous results in the last session we used only silicone membrane protected material-reduced polypropylene meshes to cover the abdominal defects. Our experiments have shown that intraperitoneal implant with silicone-covered Vypro (Ethicon)/Premilene (B. Braun Medical) mesh significantly decreases the formations of adhesion.     

Laparoscopic evaluation of abdominal adhesions with different prosthetic meshes in rabbits.

BACKGROUND: The use of prosthetic materials to reinforce the abdominal wall is associated with a low index of recurrence; however, intraperitoneal placement of a foreign body may lead to adhesions. The present investigation was designed to determine adhesion formation with commercially available meshes implanted laparoscopically in rabbits. METHODS: Three different meshes were implanted laparoscopically in 24 rabbits: polypropylene (mesh A), polypropylene and sodium hyaluronate-carboxymethylcellulose (mesh B), and polypropylene and expanded polytetrafluoroethylene (mesh C). Sites of implantation for each mesh (the left lower quadrant, right lower quadrant, and lower midline) were randomly determined so that every rabbit had all 3 meshes implanted. All animals underwent diagnostic laparoscopy after 28 days to grade adhesions and histological analysis of inflammation. RESULTS: Adhesions were noticed in 46 of the 72 meshes implanted (64%). The number of adhesions was higher for mesh C (87.5%) compared with meshes A (62.5%) and B (41.6%). The severity of adhesions was also higher for mesh C (grade I in 14, II in 6, and III in 1) compared with mesh A (grade I in 10, II in 4, and III in 1 case) and B (all of them grade II). Histological inflammatory reaction was classified as mild in 23 cases of mesh A, 15 of mesh B, and 23 of mesh C. A moderate reaction was found in 1 case of mesh A, 4 cases of mesh B, and 1 case of mesh C. Severe reaction was induced in 5 cases of mesh B. Mesh B induced a higher inflammatory reaction compared with the other meshes. CONCLUSIONS: All meshes induced adhesions of different grades. Mesh B had fewer adhesions and more intense inflammation them did the others.     

Experimental Comparison of Monofile Light and Heavy Polypropylene Meshes: Less Weight Does Not Mean Less Biological Response

Background Mesh implantation is a standard procedure in hernia repair. It provides low recurrence rate but increases complication rate due to foreign-body reaction induced by alloplastic materials in surrounding tissues. It is believed that biocompatibility of meshes may be improved by reducing their weight per meter squared (m²) and altering the implant structure. Aim The aim of this study was to evaluate the effect of weight and structure as determinants of mesh biocompatibility. Method Thirty-six Wistar rats were studied. In 12 animals, conventional polypropylene (heavy) meshes (HM) were implanted; in other 12, material-reduced (light) microporous polypropylene meshes (LM); and the remaining 12 served as a sham-operated control group. Meshes were explanted after 21 and 90 days (6 animals per group). All samples were examined by light and electron microscopies. Integration of meshes in surrounding tissue, inflammatory response, fibrotic reactions, and structural changes were recorded. Quantification of the inflammatory response was achieved by CD-68 marking of macrophages and counting their number per surface unit. Results After 21 days, there was no significant difference in thickness of surrounding connective tissue between meshes in all groups studied. After 90 days, thickness of connective tissue decreased in both groups, and fibrotic reaction in the mesh bed was significantly less in the HM group. Total amount of macrophages per millimeter squared (mm²) decreased with time in HM and LM samples but was significantly lower in the HM group on day 21 (43.5%) and day 90 (46.7%). Conclusion This study found worse biocompatibility of LM compared with HM. Thus, the amount of implanted mesh was not the main determinant of biocompatibility (expressed as successful incorporation and diminished foreign-body reaction) but the size of the pores.     

Comparative evaluation of adhesion formation, strength of ingrowth, and textile properties of prosthetic meshes after long-term intra-abdominal implantation in a rabbit

BACKGROUND: Effective laparoscopic ventral herniorrhaphy usually mandates the use of an intraperitoneal prosthetic. Visceral adhesions and changes in textile characteristics of prosthetics may complicate repairs, especially long-term. The aim of this study was to compare the adhesion formation, tissue ingrowth, and textile characteristics one year after intra-abdominal placement of the commonly used prosthetic meshes. MATERIALS AND METHODS: Forty (4 x 4 cm) meshes were sutured using absorbable suture to an intact peritoneum in 20 New Zealand white rabbits. The study groups included: polypropylene (PP) [Marlex; C.R. Bard Inc, Cranston, NJ], expanded polytetrafluoroethylene (ePTFE) [DualMesh; WL Gore, Flagstaff, AZ], ePTFE and PP (ePTFE/PP) [Composix, C.R. Bard Inc], reduced weight PP and oxidized regenerated cellulose (rPP/C) [Proceed; Ethicon, Inc, Somerville, NJ]. The meshes were explanted after one year. Adhesions were scored as a percentage of explanted biomaterials' affected surface area. Prosthetic shrinkage was calculated. The strength of incorporation and mesh compliance were evaluated using differential variable reluctance transducers. Mesh ingrowth was measured as the load necessary to distract the mesh/tissue complex. Mesh compliance was calculated as the change in linear displacement of the sensors due to applied load. The groups were compared using Student's t-test and Fisher's exact test. RESULTS: ePTFE had significantly less adhesions (0%) than both ePTFE/PP (40%) and PP (80%) groups (P < 0.001). The mean area of adhesions for the rPP/C (10%) and the ePTFE/PP (14%) groups was less than that for the PP group (40%) (P = 0.02). Prosthetic shrinkage was greatest in the ePTFE (32%) group than in any other group (P = 0.001). There were no differences in mesh incorporation between the groups. At explantation, mesh compliance in the ePTFE group was superior to other meshes (P < 0.0001). The rPP/C mesh induced the smallest change in the compliance of the tissue adjacent to the mesh (P = 0.0001). CONCLUSIONS: Prosthetic materials demonstrate a wide variety of characteristics. Although exposed PP formed the most adhesions, up to 40% of the other PP-based meshes formed adhesions despite protective barriers. The ePTFE mesh did not induce adhesions and was the most compliant, however, this prosthetic's contraction was greatest. Reduced weight polypropylene (rPP/C) mesh induced the smallest change in the adjacent tissue pliability/compliance. Understanding of the long-term effects of various prosthetic materials is important to ensure an adequate hernia repair while minimizing postoperative morbidity and patient discomfort.     

Polypropylene in the intra-abdominal position: Influence of pore size and surface area

Background. Polypropylene is a material widely used in surgery. Because of its association with formation of enterocutaneous fistulae and adhesions, direct contact between mesh and intestine is avoided. The following study was designed to investigate the adhesive potential of different polypropylene meshes when placed in direct contact with intestine. Material and methods. In an established experimental model, a total of 45 chinchilla rabbits underwent laparoscopic placement of meshes with different pore size (Group I: monofilament PP 0.6 mm, Group II: monofilament PP 2.5 mm, Group III: multifilament PP 4.0 mm) with the Intra-Peritoneal-Onlay-Mesh Technique (IPOM). The degree of adhesion formation was measured after 7, 21, and 90 days, evaluated by an adhesion score, quantified by computer-assisted planimetry, followed by histological and morphometric investigation of the perifilamental granuloma formation. Results. The heavyweight, small porous polypropylene meshes (PP 0.6) showed significantly stronger adhesion formation at all intervals of investigation compared with the lightweight meshes with a pore size >2.5 mm. Between the two different lightweight mesh variations, there was no significant difference. Granuloma formation was lowest in large-pore-size monofilament meshes (PP 2.5). Conclusion. The IPOM rabbit model is suitable for investigation of biomaterials in the intra-abdominal position. Our results show that the adhesive potential is significantly influenced by the pore size. However, the extent of the foreign-body reaction seems also to be influenced by the filament structure, respectively, the surface area, favouring monofilament material.     

Differences in biomechanical stability using various fibrin glue compositions for mesh fixation in endoscopic inguinal hernia repair

Background

In hernia surgery, mesh fixation with fibrin glue instead of tacks and sutures can demonstrably reduce postoperative morbidity without increasing recurrence rates. In some cases there are significant differences in the biomechanical properties, depending on the functional structure of the meshes. Furthermore, there are various fibrin glue products on the market and these are used for mesh fixation. This study compared the fixation strength of fibrin glues in combination with various meshes.

Methods

Three different lightweight polypropylene meshes (TiMESH? light, ULTRAPRO?, Optilene^? LP) were tested. All meshes were fixed using 2?ml of each of the three different fibrin glues (TISSUCOL^?, QUIXIL^?, EVICEL^?) and tested for their biomechanical stability. The defect in the muscle tissue used was 45?mm for a mesh size of 10?×?15?cm. Measurements were conducted using a standardized stamp penetration test, while aiming not to use a fixation strength of less than 32?N.

Results

With TISSUCOL, the fixation of Optilene LP proved to be significantly better than that of TiMESH or ULTRAPRO (97.3 vs. 47.9 vs. 34.9?N, p?<?0.001). With EVICEL, it was possible to also achieve good tissue fixation for the ULTRAPRO mesh, while the results obtained for Optilene and TiMESH were relatively poorer [114.7 vs. 92.4?N (p?=?0.056), vs. 64.3?N (p?<?0.001)]. With QUIXIL, satisfactory results were obtained only for Optilene LP (43.6?N).

Conclusion

This study showed that there were significant differences in the fixation strength of different polypropylene meshes in combination with various fibrin glues. Experiments demonstrated that for each mesh there is an optimum combination with a particular fibrin glue with respect to the fixation strength. It must now be verified whether these results can be extrapolated to clinical practice.     

An unusual cause of chronic anemia and abdominal pain caused by transmural mesh migration in the small bowel after laparoscopic incisional hernia repair

Mesh repair of incisional hernia is recommended to reduce recurrence. Recognized complications include mesh infection and fistula. Composite meshes with antiadhesive barriers were designed for intraperitoneal placement to reduce adhesion formation and fistulization to the viscera. Transmural mesh migration is a rare complication of hernia repair with composite mesh and can be present with a variety of symptoms. We report an interesting case of transmural mesh migration into the small bowel presenting with chronic microcytic anemia and abdominal pain 5 years after laparoscopic incisional hernia repair with a composite polypropylene/ePTFE mesh.     

Persistent extracellular matrix remodelling at the interface to polymers used for hernia repair

On the one hand, recurrence rates and postoperative complications following hernia repair are supposed to be influenced by the kind of mesh material used. On the other hand, an impaired collagen metabolism and cleavage within connective tissue has been suggested as decisive factor in the pathogenesis of recurrent hernia formation. The aim of our study was, therefore, to analyze the impact of commonly used mesh materials on quality of collagen deposition, expression of collagenases (matrix metalloproteinases; MMP-1/MMP-13), and specific tissue inhibitors of MMPs (TIMPs) in an animal study. Four different mesh materials were used (Prolene = polypropylene, Mersilene = polyester, and Vypro and Vypro II = combinations of polypropylene and polyglactin) and implanted as abdominal wall replacement in 60 male Wistar rats. Mesh samples were explanted after 3, 21, and 90 days and investigated using immunohistochemistry (expression of MMP-1/MMP-13 and TIMP-1) and cross-polarization microscopy (percentage of collagen type III to overall collagen). Besides an insufficient collagen composition with an increased percentage of collagen type III, we found a complex expression of collagenases and their inhibitors combined with a persistent chronic foreign-body reaction even 90 days after implantation. Except for TIMP-1 expression, which was significantly related to a lowered amount of inflammatory (r = -0.980, p = 0.02) and connective tissue formation (r = -0.951, p = 0.049), there was no relation to the expression of collagenases (MMP-1/MMP-13) with regard to the amount of inflammatory and connective tissue formation despite partly significant differences between implanted polymers.