Expanded polytetrafluoroethylene membrane for the prevention of peridural fibrosis after spinal surgery: a clinical study

Peridural fibrosis developing after laminectomy may cause pain that can necessitate reoperation. Many materials have been used as a barrier to invasion of fibrous tissue into the vertebral canal, but the ideal material has not been found. Various studies in animals have achieved favourable results with an expanded polytetrafluoroethylene (ePTFE) membrane. In a prospective, randomized study, we compared postoperative results in 33 patients who had an ePTFE membrane implanted to cover the defect caused by laminectomy during lumbar spine decompression with the results in 33 patients in whom no material was implanted. At operation, an ePTFE membrane was placed after the decompression procedure to cover the laminectomy defect completely. Systematic clinical and MRI follow-up evaluations of patients with and without the membrane were conducted 3, 6, 12, and 24 months postoperatively. The effect of ePTFE membrane implantation over laminectomy sites on postoperative peridural fibrosis, pain and neurological claudication was assessed. The ePTFE-membrane group had a significantly lower rate of epidural fibrosis on MRI (P < 0.0001) and of clinical manifestations of radiculalgia (P = 0.002) compared with the no-material group. Epidural fibrosis that occurred in the ePTFE group was generally less extensive than that in the no-material group. There was no significant difference in the rate of postoperative claudication in the two groups. Significantly more seromas occurred in the ePTFE group (P = 0.0002). There were no infections or other complications in either group. The results showed that placement of an ePTFE spinal membrane over the laminectomy defect produced by lumbar spine surgery provided a physical barrier to invasion of fibrous tissue into the vertebral canal, and patients with the membrane had less postoperative radicular pain. Received: 24 November 1997 Revised: 26 November 1998 Accepted: 2 December 1998     

椎板切除术术后硬膜外纤维化预防的研究进展

正椎板切除术术后硬膜外过度的纤维增生会造成椎管狭窄,压迫硬膜囊及神经根,或与其粘连,限制神经根活动,引起术后疼痛复发,即腰椎手术失败综合征(FBSS),而这种疼痛难以通过药物等非手术治疗途径得到缓解[1]。由于纤维组织与硬膜粘连,二次手术时很难将硬膜与硬膜外组织分离,甚至会造成硬膜囊的撕裂,增加了二次手术的难度,延长了手术时间,二次手术后FBSS依然可能发生。有研究发现,随着手术次数增加,第二、三次手术的成功率     

Epidural scar tissue formation after spinal surgery: an experimental study

Summary Extensive epidural scar formation is a wellknown complication after spine surgery. Fibrous adhesions around nerve roots are a major reason for recurrent neurological symptoms following lumbar discectomy. A large variety of materials, implanted onto the dura, have been used to prevent or reduce laminectomy membrane, with conflicting results. We therefore carried out an experimental study in dogs to compare those materials that seemed to be most suitable. In each of 30 adult beagles, three lumbar laminectomies were performed. Each level was covered with a different material — free autologous fat graft, cellulose mesh, Gelfoam or triamcinolone suspension. In a control group nothing was implanted. After 7 days or 1, 3 or 6 months the animals were killed. The lumbar vertebral columns were harvested and prepared for further histological examination. To compare the results, we designed a new classification scheme (scar index). The data were obtained without knowledge of implanted material or time since operation. We found that free autologous fat grafts are able to reduce epidural scar formation in a high proportion of cases, especially after 3 and 6 months; cellulose mesh showed the worst results. We conclude that free autologous fat grafts are superior to other materials because of simple operative handling, good compatibility and effective prevention of laminectomy membrane.     

人工硬膜修补硬脊膜及预防椎管内粘连的实验观察

目的：观察人工硬膜（胶原海绵）敷贴修补硬脊膜破损的组织病理学反应和预防术后硬脊膜周围纤维化粘连的效果.方法：实验A,30只家兔随机分成3组,每组10只,造成硬脊膜纵形破损,随机分别应用人工硬膜、明胶海绵敷贴裂口处和旷置.术后8d和30d处死动物,行肉眼和组织学观察,同时进行缺损区瘢痕组织的成纤维细胞密度评级.实验B,12只家兔随机分成2组,每组6只,进行T10和T12椎板切除,使硬膜裸露,T10缺损旷置,作为空白对照,T12缺损用人工硬膜或明胶海绵进行覆盖,术后30d,处死动物取材.肉眼和组织学观察硬膜缺损处并按有关的组织学评级标准半定量分析.结果：实验A中人工硬膜在体内未引起不良反应.组织学观察发现植入物内有大量的成纤维细胞长入、毛细血管形成和胶原沉积,植入物有降解趋势.实验B中与空白对照组比较,人工硬膜组硬脊膜周围粘连较轻（P＜0.05）.结论：人工硬膜（胶原海绵）作为一种硬脊膜移植材料具有较好的组织相容性,有促进组织修复作用;早期能防止硬脊膜外瘢痕组织向椎管内侵入,起到空间屏障作用,在一定程度上减轻了纤维瘢痕组织侵入椎管所造成的硬脊膜周围纤维性粘连.     

脊柱膜与生物蛋白胶联合应用预防硬膜外粘连的实验研究

目的观察椎板切除术后联合使用脊柱膜与生物蛋白胶预防硬膜外粘连的效果,探讨从三维上预防粘连的最佳方案。方法本课题采用动物实验,运用拉丁方实验设计,分别做无植入（A组）,植入生物蛋白胶（B组）,脊柱膜（C组）,脊柱膜和生物蛋白胶（D）于兔的4个节段,术后4周对椎板切除部位进行大体观察、组织学观察及MR I检查,比较各组瘢痕形成和粘连情况。结果①A组可见大量瘢痕组织增生,以硬膜囊后方明显,粘连严重。②B组防粘连的效果差。③C组的防粘连的效果优于A组和B组,但差于D组。④D组,不但能够防止后方肌肉及疤痕组织的长入,而且可防止前方、周围硬膜及神经根的粘连。结论联合使用硬体材料脊柱膜和流体材料生物蛋白胶是防止椎板切除术后硬膜粘连的最佳方案。     

Outcomes of decompression surgery for lumbar spinal stenosis in elderly diabetic patients

The purpose of this study was to assess and compare the outcome of surgical decompression for spinal stenosis in diabetic and non-diabetic elderly patients. This is a retrospective chart analysis conducted in a university affiliated referral hospital. The participants were consecutive patients, age 65 and older, undergoing laminectomy for spinal stenosis during 1990–2000. We assessed patients clinical and demographic data, procedures, perioperative complications, preoperative and postoperative pain intensity, basic activities of daily living (BADL), patients satisfaction, the need for repeated surgery, and overall mortality. A total number of 62 elderly diabetic group (DG) patients undergoing decompression surgery for spinal stenosis were compared with a sex and age-matched non-diabetic control group (CG) at baseline, and a mean of 40.3 months thereafter. We found that the DG patients had more pain (p=0.042), and suffered more frequently from neurogenic claudication (p=0.0018), motor weakness (p=0.021) and numbness of the affected limb (p=0.0069) than the CG patients. Nocturnal pain was reported in 24% of the DG patients. Pain relief was successfully achieved in both groups (p<0.001), but the patients satisfaction was greater in the non-diabetic patients (p=0.0067). Revision surgery was more frequently performed in the DG than the CG (non-significant difference), and the time interval for such a second intervention was shorter (p=0.04) in the DG. A higher rate of post-operative complications was observed in the DG (p<0.0001). It is concluded that surgical treatment of elderly diabetic patients suffering from spinal stenosis improves BADL and ameliorates pain, but the results remain worse than those observed in non-diabetics. The outcome of diabetic patients depends upon the presence of other comorbidities, concurrent diabetic neuropathy, duration of diabetes and insulin treatment. Successful postoperative pain reduction remained the strongest factor associated with patients satisfaction.     

多孔磷酸钙人工椎板应用的实验研究

目的：观察多孔磷酸钙人工椎板（ＰＣＰＡＬ）对全椎板切除后硬膜外纤维化的预防作用。方法：手术切除２０只家兔的Ｌ４、Ｌ６椎板。其中一个节段植入多孔磷酸钙人工椎板，另一个节段作空白对照。术后２、４、８、１８和２３周处死家兔作病理观察、ＣＴ扫描和三维结构重建、计算机图像分析。结果：ＰＣＰＡＬ具有良好的生物相容性，较好的生物降解能力和引导骨组织生长的能力。实验节段的硬膜外疤痕量和硬膜粘连均明显少于空白节段。结论：ＰＣＰＡＬ对全椎板切除后硬膜外纤维化及纤维疤痕组织对脊髓的压迫有预防作用。     

腰椎手术后硬膜外腔瘢痕预防的实验研究

目的比较腰椎手术后硬膜外放置明胶海绵、几丁糖和高分子量的透明质酸钠 (sodium hyaluronate,HA)对术后硬膜外瘢痕形成的预防作用。方法 96只 Wistar大鼠被随机分成四组,每组 24只。一组为对照组,其它三组分别于单侧半椎板切除术和椎间盘破坏术关闭切口前在硬膜外腔放置明胶海绵、几丁糖和高分子量 HA。分别在术后第 2、 4、 8、 12周时,每组各取 6只大鼠进行大体标本、组织切片 (HE、 VG和免疫组化染色 )和透射电镜观察。对术后硬膜外瘢痕的多少和椎管的大小进行计算机图像分析和统计学处理。检测对照组和高分子量 HA组大鼠脑脊液中的 HA浓度。结果几丁糖和高分子量 HA组的硬膜外瘢痕比其它各组显著减少 (P< 0.05);椎管的大小在各组各时段差异没有显著性意义;在各组各时段均可见到纤维环的环状纤维未能修复椎间盘手术带来的连续性中断。所有脑脊液标本中 HA浓度最高的 2例在 2周时的 HA组。结论几丁糖和高分子量 HA能减少后路腰椎间盘术后的硬膜外瘢痕的形成;评价材料对硬膜外瘢痕影响的同时,也要考虑到其对椎间盘破口愈合的影响;在硬膜外腔放置各种材料时应考虑到其对中枢神经系统的潜在影响。     

持续冲洗预防硬膜外术后粘连的实验研究

目的观察持续灌洗联合透明质酸钠局部应用对兔硬膜外粘连的预防效果。方法对25只成年健康新西兰白兔行椎板切除术,每只兔的背部均为3处切口,分别切除L1、L4、L7棘突、椎板,显露硬脊膜囊。将术后存活的22只白兔施行手术的66个节段随机分成3组：对照组（直接缝合）、几丁糖组（放置几丁糖膜）和冲洗组（持续灌洗72h后在拔管前注入透明质酸钠）。术后12周取材,进行大体和光镜检查并采用Rydell评分标准和改良Nussbaum评分标准比较组间差异。结果对照组硬膜外大量瘢痕组织填充,与周围组织难以分离;几丁糖组硬膜外瘢痕增生不明显,与硬膜之间有明显间隙,可与硬膜分离;冲洗组可见硬膜与肌肉组织之间为脂肪浸润和少量瘢痕出现,与硬膜部分粘连,易于分离。对3组的Rydell评分和改良Nussbaum评分结果进行两两比较,冲洗组和几丁糖组之间差异无统计学意义（P〉0.05）;分别将此两组与对照组进行比较,差异均有统计学意义（P〈0.05）。结论持续冲洗和局部应用透明质酸钠是预防硬膜外粘连的有效方法 。     

预防硬膜外瘢痕粘连的实验研究

目的通过动物实验观察几丁糖对预防椎板切除术后硬膜瘢痕粘连的作用。方法24只成年山羊行腰2腰4短节段椎弓根钉系统固定及取自体髂骨行后外侧植骨融合术,腰3水平全椎板切除,切除口约3cm×1.5cm,腰3硬膜外分别放置几丁糖或空白对照各12只。于术后24周进行大体形态、组织学观察,并进行硬膜外瘢痕粘连程度分级。结果几丁糖组硬膜与瘢痕无明显粘连,空白对照组硬膜与瘢痕紧密粘连。结论几丁糖能有效地预防椎板切除术后硬膜外瘢痕粘连。     

Reduction of epidural fibrosis and dural adhesions after lamina reconstruction by absorbable cement: an experimental study

Background contextPost-laminectomy epidural fibrosis complicates revision spine surgery and is implicated in cases of “failed back syndrome.” Several materials have been used to minimize epidural fibrosis with varying results.PurposeThe aim of this study was to examine the impact of reconstruction of laminectomy site with a type of absorbable cement (Jectos) to reduce epidural fibrosis.Study designThis investigation is an experimental controlled study, which is designed to evaluate the preventive effects of laminectomy site reconstruction in rat laminectomy model.MethodsTwenty wistar rats were included in this study and divided randomly to two equal groups, namely, subject and control. In both groups, laminectomy was performed in L2 and L4 levels. Control group received no additional treatment. In the subject group, L4 levels were reconstructed by Jectos and L2 levels were non-reconstructed as internal controls. Six months after surgery the rats were sacrificed and the dural adhesion and epidural fibrosis were evaluated macroscopically and microscopically. The study was financially supported by Brain and Spinal Cord Injuries Repair Center. None of the authors have any conflict of interest.ResultsNon-reconstructed levels in both groups showed dense epidural fibrosis with marked dural adherence. L4 reconstructed levels in subject group showed reduced epidural fibrosis macroscopically (p=.024) and microscopically (p=.041). No foreign body reaction or ossification occurred at reconstructed sites.ConclusionsIn the present study, lamina reconstruction with absorbable cement was a safe method that significantly reduced post-laminectomy epidural fibrosis and dural adhesions in rat laminectomy model.     

Cost effectiveness of lumbar disc surgery and of a preventive treatment for peridural fibrosis

Study design: This study used a retrospective modeling approach to predict the sequelae, treatment patterns, and economic outcomes that patients treated or not treated with ADCON^®-L Anti-Adhesion Barrier Gel can experience over a 1-year period following first-time surgery for herniated lumbar disc. The study was designed for and carried out in the Netherlands. Objectives: The study was carried out to investigate the economic impact of ADCON-L application in lumbar disc surgery. Summary of background data: Patients with a poor outcome following primary lumbar disc surgery represent a medical challenge to physicians and an economic concern, as they often experience long-term sequelae. Patients who have failed to benefit adequately from primary surgery tend to be very expensive patients, receiving a costly array of conservative therapies, diagnostic measures and, sometimes, repeat surgery. Methods: A Markov model was constructed to integrate the retrospectively assessed treatment patterns, economic outcomes, and costs of Dutch lumbar disc patients with the analysis of the benefits of ADCON-L as shown in a clinical study population derived from the preliminary results of a multicenter, randomized clinical trial of ADCON-L in Europe. Results: Use of ADCON-L can recoup 20% of its proposed initial cost of NLG 1000 in direct health care savings during the first year after primary surgery. When indirect/societal as well as direct costs are considered, for every Dutch guilder invested in ADCON-L treatment, savings of NLG 1.8 are achieved. Conclusions: In patients treated with ADCON-L during lumbar discectomy, the quality of surgical outcome improves while cost per successful outcome is reduced.This study was supported by a grant from Gliatech Inc., Cleveland, Ohio, USA     

Role of peridural fibrosis in the failed back: a review

Failed back surgery syndrome (FBSS) is the presence of persistent, disabling pain in the hip, thigh, leg, or lower back of a patient who has undergone a laminectomy or discectomy. Some degree of FBSS is found in approximately 15% of such patients. There may be a direct relationship between the extent of pathology found during the initial surgical procedure and the probability that FBSS will develop. Although FBSS is usually due to improper diagnosis and surgery, another important cause is peridural fibrosis. Part of the answer may have to do with neuromechanics. In a healthy person, pain associated with dural and nerve root movement does not typically occur when performing activities of daily living. In contrast, in a person with peridural scarring, the dura and nerve roots are bound by fibrosis, and putting traction on the nerve roots and dura by back and limb movement produces pain. This pain is aggravated by the presence of inflammation at the surgical site. Research has shown that disc herniation activates the arachidonic acid cascade, resulting in the production of prostaglandins E₁ and E₂ and leukotriene B, substances that contribute to an inflammatory process that persists after discectomy. In an attempt to inhibit peridural fibrosis, methylprednisolone, polyethylene films, and fat grafts have been applied to the dura after discectomy. These experimental treatments have had limited success. Development of a therapy that reliably prevents peridural adhesive fibrosis will reduce the incidence of FBSS.Sponsored by the University of Tennessee, Memphis, Department of Neurosurgery, and Gliatech Inc., Cleveland, Ohio, USA     

脊柱手术后疼痛综合康复治疗的病例对照研究

目的:探讨干扰电为主的综合康复治疗脊柱手术术后疼痛的临床效果。方法:回顾分析2004年1月至2008年12月行脊柱手术后疼痛治疗166例情况,分别应用单纯镇痛药物及联合干扰电治疗。其中单纯药物治疗46例,男22例,女24例;平均年龄(51.0±6.5)岁;药物联合干扰电治疗120例,男50例,女70例;平均年龄(48.0±5.6)岁。治疗前,药物治疗组Ⅲ度疼痛4例,其中3例是椎管狭窄手术,1例是先天性椎弓峽部裂;Ⅱ度疼痛42例。药物联合干扰电治疗组Ⅲ度疼痛17例,其中13例是椎管狭窄手术,4例是先天性椎弓峽部裂;Ⅱ度疼痛103例。治疗前及治疗期间,根据世界卫生组织(WTO)疼痛程度划分标准评定病例疼痛缓解情况进行比较分析。结果:两组病例疼痛级别构成比(Ⅲ度/Ⅱ度/Ⅰ度):治疗第3日,药物联合干扰电治疗组为1/96/23,单纯药物治疗组为4/42/0;治疗第7日,药物联合干扰电治疗组为0/17/103,单纯药物治疗组为2/44/0;治疗第14日,药物联合干扰电治疗组为0/0/120,单纯药物治疗组为0/4/42。经秩和检验3个时间点均显示病例疼痛程度分布差异有统计学意义,药物联合干扰电治疗组中Ⅲ度疼痛者或Ⅱ度疼痛者所占比例均较单纯药物治疗者明显下降。结论:药物联合干扰电治疗可加快改善患者的术后疼痛症状,缩短患者的住院时间。     

三七凝胶预防椎板切除术后粘连的实验研究

目的:从大体、组织形态学观察分析三七凝胶预防椎板切除术后粘连的有效性和可行性。方法:84只Sprague-Daw ley大鼠(SD大鼠)按单纯随机方法分为4组:三七凝胶组(NG)、单纯三七组(N)、空白对照组(C)、纤维蛋白胶组(FG),每组21只。切除L1-L2右侧椎板,分别在硬膜囊周围涂抹三七凝胶、三七浓缩液、生理盐水、纤维蛋白胶。每组大鼠分别在术后2、4、8周处死。各组在每个时间段各处死7只,其中1个标本作大体观察瘢痕的量、范围、致密程度以及解剖过程中硬膜囊的完整性,其余6个标本作组织切片(HE染色)观察术后硬膜外瘢痕粘连的程度、计算椎管内粘连百分率。结果:术后各个时间段三七凝胶组椎管内预防粘连百分率明显优于单纯三七组、纤维蛋白胶组、空白组(P<0.05或P<0.01)。结论:三七凝胶可以作为一种良好的材料用于预防椎板切除术后硬膜外瘢痕粘连。     

Recurrent pain after lumbar discectomy: the diagnostic value of peridural scar on MRI

The association between peridural scarring and recurrent pain after lumbar discectomy is much debated. A recently published study found that patients with extensive peridural fibrosis were 3.2 times more likely to experience recurrent radicular pain than those with less extensive scarring. This finding may lead to an overestimation of peridural fibrosis in clinical practice. In a retrospective study we analyzed the records of 53 patients who underwent a lumbar MRI because of recurrent pain after first unilateral microdiscectomy. Patients were classified as those with radicular or non-radicular pain according to history and clinical findings. The diagnosis was confirmed by spinal anesthetic block. The extension of scarring was compared between the two groups of patients. The amount of epidural fibrosis was examined on contrast-enhanced MRI in axial slices subdivided into four quadrants. The amount of fibrosis was divided into four stages in each affected quadrant. We found no differences regarding the amount of peridural fibrosis between patients with radicular pain and patients with non-radicular pain. We conclude that the extent of peridural scarring as defined by MRI is of minor value in the differential diagnosis of recurrent back and leg pain after lumbar microdiscectomy. Received: 17 October 1998 Revised: 3 August 1999 Accepted: 18 August 1999     

The influence of intervertebral disc tissue on anterior spinal interbody fusion: an experimental study on pigs

Intervertebral disc has been shown to be related to low back pain and nerve root injury in pathologic conditions. However, little is known about its influence on spinal fusion. With the development of minimal invasive operations, such as laparoscopic anterior spinal fusion with cages, insufficient discectomy may occur. With its inflammatory properties, the residue nucleus pulposus may have an effect on spinal fusion. In this study, a two-level lumbar spine interbody fusion (L3/4, L5/6) with a Brantigan cage was performed on ten Danish Landrace pigs. Each level was randomly assigned to one of the following methods: (1) implantation of Brantigan cage filled with autogenous iliac crest bone graft, or (2) implantation of Brantigan cage filled with a mixture of autograft and the nucleus pulposus tissue harvested from the disc level in which it was to be inserted. Each level was stabilized with two staples. The pigs were followed for 12 weeks in the same standardized condition. After sacrifice, the lumbar spines were taken out, and plain X-ray, computed tomographic (CT) scanning and histomorphometry were performed to study the fusion mass inside the cages. From plain radiographs, new bone formation could be seen inside and around the cage. CT evaluation showed that the nucleus pulposus level had a 20% (2/10) fusion rate, while the pure autograft level had a 70% (7/10) fusion rate ( P=0.07). The histological fusion rate was even lower in the nucleus pulposus level (10%), and was significantly different from the autograft level (70%, P=0.02). Histomorphometric parameters of new bone formation, bone marrow space and fibrous tissue differed significantly between the two levels ( P=0.04; P=0.02; P=0.04 respectively). We conclude that when nucleus pulposus is mixed with the autogenous bone graft, it can delay or decrease the bone formation inside the cage, thus influencing the final fusion.     

The value of expanded polytetrafluoroethylene in preventing early re-ossification after craniosynostosis surgery: an experimental animal study in the rat

Summary Background. Early re-ossification at the suturectomy site after craniosynostosis surgery remains an important problem. Many surgical methods have been used to address this, including placement of various types of absorbable and non-absorbable material between the bone edges at the site. This experimental study investigated the value of expanded polytetrafluoroethylene (ePTFE) membrane as a barrier to calvarial reclosure after craniosynostosis surgery in rats.Method. Thirty-five 2-week-old Sprague-Dawley rats were divided into two groups. In Group A (n=17), ePTFE membranes were placed in the defect formed by a left coronal suturectomy. The Group B rats (n=18) underwent left coronal suturectomy only. Animals were sacrificed at 1, 2 and 4 months postoperatively. In each case, the skull was removed and the operative site was examined for fibrosis, new bone formation, bone bridging, neovascularization and inflammatory response.Findings. The two groups were similar with respect to neovascularization and new bone formation. By the end of the fourth postoperative month, 50% of the Group B specimens showed fibrosis and 50% showed bridging between the bone edges at the suturectomy site. In contrast, at the same stage in Group A, only 16.6% of the specimens exhibited a small amount of fibrosis, and none showed bone bridging between the edges.Interpretation. Expanded PTFE is one of the most inert materials used in surgery. The study showed that inserting ePTFE membrane as a barrier between the bone edges at the suturectomy site prevents early re-ossification after craniosynostosis surgery in rats.     

钛网椎管重建对硬膜外瘢痕粘连形成影响的实验研究

[目的]探讨全椎板切除后采用钛网椎管重建能否减少术后硬膜外瘢痕粘连形成.[方法]以16只成年家兔为实验对象,随机分成A、B两组,每组8只.建立L3椎体全椎板切除模型,A组为对照组,建模后不做特殊处理,彻底止血后闭合切口;B组作为实验组,建模后将“V”形钛合金网固定并覆盖于减压节段之上,完成椎管重建.于术后8周对手术部位行X线片检查,对比观察骨质愈合及钛网位置情况,随后处死实验动物,对椎板切除部位进行大体和组织学观察,并分别进行硬膜外粘连程度等级评分,结果采用等级资料的秩和检验进行比较.[结果]所有实验动物伤口均一期愈合.术后8周X线提示实验组中有6例可见到新生骨组织与钛网融合成片,形成椎板样结构,对照组中亦有4例硬膜外可见到再生的高密度骨组织.两组动物间椎板切除处骨愈合情况无统计学差异(P＞0.5).B组的Rydell-Balazs大体粘连度评分,He-Revel组织学评分均显著优于A组(P＜0.5).[结论]本实验结果显示全椎板切除后钛网椎管重建可减少术后硬膜外瘢痕的形成,并且钛网的存在未影响椎板切除处的骨愈合.