Adhesion formation of a polyvinylidenfluoride/polypropylene mesh for intra-abdominal placement in a rodent animal model

Background  Effective laparoscopic ventral herniorrhaphy mandates the use of an intraperitoneal mesh. Visceral adhesions and shrinkage of prosthetics may complicate repairs. The aim of this study was to compare adhesion formation, mesh shrinkage and tissue ingrowth after intra-abdominal placement of a novel two-component monofilament mesh structure made of polypropylene (PP) and polyvinylidenfluoride (PVDF) with current alternatives. Materials and methods  Forty Sprague-Dawley rats were used in this study. Mesh samples were fixed as intra-abdominal only mesh at the right lateral abdominal wall. The study groups were: PVDF+PP (polypropylene parietally and polyvinylidenfluoride viscerally), PP+Col (polypropylene with a collagenoxidized film), ePTFE (smooth surface viscerally and a textured surface parietally), and PP (a pure polypropylene mesh serving as control). The meshes were explanted after 30 days. Adhesions were scored as a percentage of explanted biomaterials’ affected surface area; prosthetic shrinkage was calculated. Foreign-body reaction to mesh materials was measured by investigating the amount of inflammatory infiltrate and fibrotic tissue formation. Results  In terms of adhesion score, the pure PP mesh showed the highest values followed by the ePTFE, PVDF+PP, and PP+Col meshes. Quantitative assessment of adhesion area revealed a significantly higher value of the pure PP mesh sample (62.0 ± 22.1%) compared with the PP+Col (26.8 ± 12.1%) and the PVDF+PP mesh (34.6 ± 8.2%). Percentage of shrinkage showed a significantly higher value of the ePTFE mesh (52.4 ± 13.9%) compared with all other mesh modifications (PP+Col 19.8 ± 13.9%, PVDF+PP 19.9 ± 7.0%, and PP 26.8 ± 9.5%). Inflammatory infiltrate was significantly reduced in the PVDF+PP mesh group compared with all other mesh samples. Conclusion  The use of the novel two-component monofilament mesh structure made of polypropylene and polyvinylidenfluoride was found to be favorable regarding adhesion formation and mesh shrinkage compared to conventional mesh materials used for intra-abdominal placement.     

Intraabdominal adhesion formation of polypropylene mesh Influence of coverage of omentum and polyglactin

Background Adhesions after intraabdominal surgical procedures are related to high morbidity and mortality. Biomaterials, particularly those made of polypropylene, in the intraabdominal position have to be considered as pathophysiological cofactor in a multifactorial process of adhesion formation. To investigate the adhesive potential induced by the biomaterial, an animal model was performed. In addition, the influence of coverage by omentum or a polyglactin barrier was investigated.Methods In, 18 Chinchilla rabbits the biomaterial was placed laparoscopically using the intraperitoneal onlay mesh technique. Using this model, a polypropylene–polyglactin mesh compound (PPMC) was used with three different implantation techniques: group 1, PPMC implantation without coverage (PPMC): group 2, PPMC implantation with additional omentum coverage (PPMC-O): and group 3, PPMC implantation with coverage of an absorbable polyglactin mesh (PPMC-V). The degree of adhesion formation was measured 90 days after implantation by computer-assisted planimetry. Morphometric examination followed the explantation analyzing the amount of foreign body response.Results We found a significant reduction of adhesion formation for the PPMC and PPMC-O groups compared to the PPMC-V group, in which dense adhesions were found. Morphometric investigations of the perifilamental granulomas of the pure (PPMC) group revealed a typical foreign body reaction with a mild to moderate fibrosis around all mesh fibers. However, tissue specimens of the PPMC-O and PPMC-V groups indicated a similar inflammatory reaction but significantly increased connective tissue formation around the polymer fibers compared to the pure PPMC group.Conclusion The intraabdominal placement of a pure PPMC shows a neoperitonealization and perifilamental collagenous ingrowth with almost no adhesions. Coverage with omentum (PPMC-O) or polyglactin mesh (PPMC-V) resulted in a significant increase in inflammation and perifilamentary connective tissue formation.     

腹腔镜下腹腔内网片植入术治疗成人腹股沟疝(546例中期随访结果)

目的总结腹腔镜下腹腔内网片植入术（intraperitoneal onlay polytetrafluoroethylene mesh repair，IPOM）治疗成人腹股沟疝的中期随访结果。方法回顾分析2002年6月～2004年12月两家医院以腹腔镜IPOM方法治疗的546例603侧腹股沟疝。以钉合枪固定补片，利用脐内侧韧带腹膜覆盖网片的内侧。结果除2例因疝缺损太大中转开放手术外，手术均获成功，无手术并发症。术后并发症5例，均为血清肿，理疗后吸收。手术时间25-40min，平均31min。住院时间36-72h。平均46h。随访18-48个月，平均28个月，6例复发（复发时间30-45个月，平均38．2月），复发率0．995％。结论腹腔镜下IPOM治疗成人腹股沟疝效果确切、创伤少、并发症少、术后恢复快，充分体现微创优点。     

Laparoscopic antireflux surgery: Tailoring the hiatal closure to the size of hiatal surface area

Background

The closure of the hiatal crura has proven to be a fundamental issue in laparoscopic antireflux surgery. In particular, the use of prosthetic meshes for crural closure results in a significantly lower rate of postoperative hiatal hernia recurrence with or without intrathoracic migration of the fundic wrap. The aim of the present study was to evaluate different methods of crural closure depending on the size of the hiatal defect by measuring the hiatal surface area.

Methods

Fifty-five consecutive patients (mean age = 53 years) with symptomatic gastroesophageal reflux disease (GERD) were scheduled for laparoscopic antireflux surgery (LARS) in our surgical unit. Intraoperatively, the length, breadth, and diameter of the hiatal defect was measured using an endoscopic ruler. In every patient, the hiatal surface area (HSA) was calculated using an arithmetic formula. Depending on the calculated HSA, hiatal closure was performed by (1) simple sutures, (2) simple sutures with a 1 × 3-cm polypropylene mesh, (3) simple sutures with dual Parietex^® dual mesh, or (4) “tension-free” polytetrafluoroethylene BARD Crurasoft^® mesh.

Results

Twenty-six patients (47.2%) underwent laparoscopic 360° “floppy” Nissen fundoplication. The remaining 29 patients (52.8%) with esophageal body motility disorder underwent laparoscopic 270° Toupet fundoplication. Mean calculated HSA in all patients was 5.092 cm². Thirty-two patients (58.2%) with a smaller hiatal defect (mean HSA = 3.859 cm²) underwent hiatal closure with simple sutures (mean number of sutures: = 2.0). In 12 patients (21.8%) with a mean HSA of 7.148 cm², hiatal closure was performed with a 1 × 3-cm polypropylene mesh in addition to simple sutures. Five patients with a mean HSA of 6.703 cm² underwent hiatal closure with Parietex mesh, and in the remaining six patients, who had a mean HSA of 8.483 cm², the hiatus was closed using BARD Crurasoft mesh. For a mean followup period of 6.3 months, only one patient (1.8%) developed a postoperative partial intrathoracic wrap migration.

Conclusion

Measurement of HSA with subsequent tailoring of the hiatal closure to the hiatal defect is an effective procedure to prevent hiatal hernia recurrence and/or intrathoracic wrap migration in laparoscopic antireflux surgery.

     

Influence of polyglecaprone 25 (Monocryl) supplementation on the biocompatibility of a polypropylene mesh for hernia repair

Background: Supplementary polyglecaprone 25 (Monocryl) monofilaments were added to a lightweight pure monofilament polypropylene mesh (PP mesh) to improve intraoperative handling (PP+M mesh). This study was designed to evaluate the influence of this additional supplementation on the biocompatibility in a rodent animal model. Methods: Two mesh materials, a composite mesh (PP+M) and the pure polypropylene variant (PP), were compared after subcutaneous implantation in a standardized rat model. Histological analysis of the inflammatory response was performed after 28, 56 and 84 days of implantation. Material absorption, inflammatory tissue reaction, fibrosis and granuloma formation were investigated, as well as the percentage of proliferating and apoptotic cells at the interface. Results: Both mesh materials showed a slight foreign body reaction involving mainly macrophages and foreign body giant cells. Total absorption of the Monocryl filaments of the PP+M mesh occurred between 56 and 84 days of implantation. Both the inflammatory and the fibrotic reaction were decreased (n.s.) in the PP+M mesh group compared to the pure PP mesh. Whereas the percentage of proliferating cells showed no significant difference, the rate of apoptotic cells was significantly decreased in the PP+M mesh group over the whole implantation period. Conclusion: Compared to the pure polypropylene mesh, our data confirm that the use of a polypropylene mesh supplemented with absorbable Monocryl filaments is feasible without additional short-term mesh-related complications in the experimental model or negative side effects on biocompatibility.     

Transvaginal mesh technique for pelvic organ prolapse repair: mesh exposure management and risk factors

Prosthetic reinforcement in the surgical repair of pelvic prolapse by the vaginal approach is not devoid of tolerability-related problems such as vaginal erosion. The purposes of our study are to define the risk factors for exposure of the mesh material, to describe advances and to recommend a therapeutic strategy. Two hundred and seventy-seven patients undergoing surgery due to pelvic prolapse with transvaginal mesh technique were included in a continuous, retrospective study between January 2002 and December 2003. Thirty-four cases of mesh exposure were observed within the 2 months following surgery, which represents an incidence of 12.27%. All the patients were medically treated, nine of whom were found to have completely healed during the check-up performed at 2 months. In contrast, 25 patients required partial mesh exeresis. Risk factors of erosion were concomitant hysterectomy [OR=5.17 (p=10⁻³)] and inverted T colpotomy [OR=6.06 (p=10⁻²)]. Two technical guidelines can be defined from this study as regards the surgical procedure required in order to limit mesh exposure via the vaginal route. The uterus must be preserved, and the number and extent of colpotomies needed to insert the mesh must be limited.     

Ultrasound detection of visceral adhesion after intraperitoneal ventral hernia treatment: A comparative study of protected versus unprotected meshes

Intraperitoneal (IP) ventral hernia repair has been proposed with the advantages of reducing dissection, operative time, and postoperative pain. The IP position of the mesh is suspected of increasing the risk of visceral adhesion and inducing complications. To overcome these drawbacks, a mesh protected on one side by a hydrophilic resorbable film (Parietex Composite) has been validated [1]. Using a previously described ultrasound procedure [2], the purpose of this study was to compare the rate of visceral adhesion after intraperitoneal placement of a polyester mesh versus this protected mesh. Fifty-one patients who received a Parietex Composite mesh were prospectively compared to a retrospective series of 22 consecutive asymptomatic patients who received a Mersilene mesh. To objectively assess visceral adhesion toward the abdominal wall, an ultrasound (US) specific examination was firstly validated and secondly used to evaluate the adhesion incidence in both groups. Both groups were equivalent in terms of inclusion criteria and body mass index (BMI). Pre-operative US versus perioperative macroscopical findings determined the following parameters: sensitivity 83%, accuracy 78%, negative predictive value 81%. Using this procedure, 77% of the patients exhibited visceral adhesion to the mesh in the Mersilene group, against 18% in the Parietex Composite group (P<0.001, chi-square). US examination represents a suitable tool to evaluate postoperative adhesions to the abdominal wall. Using this procedure, a significant reduction of visceral adhesion in the Parietex Composite group was shown.An erratum to this article can be found at     

Comparison of biomaterials in the early postoperative period

Background: Laparoscopic hernia repair necessitates the use of biocompatible materials. A prospective, double-blind study was conducted to compare two different polypropylene meshes. Methods: The study included 40 men with primary inguinal hernia undergoing transabdominal preperitoneal polypropylene mesh repair. In 20 of these men, a monofile, heavy-weight, rigid mesh was implanted (group A), and in the remaining 20 men, a smooth, heavy-weight variant of polypropylene mesh was implanted (group B). Complications, pain development, inability to work, physical conditions, testicular volume, and blood circulation were documented. Results: Reconvalescence in group A was slower than in group B. In group A, the postoperative values of the visual scales for pain development were higher; inability to work was 7.3 days longer; urologic disorders were worse; activities of everyday life were more reduced; and SF-36 data showed a significant reduction of physical problems (p < 0.05). Conclusions: The polypropylene mesh variant seems to be more compatible with the human organism than conventional mesh. Not only the material, but also the structure seems to influence the comfort of the mesh.     

Titanium coating of a polypropylene mesh for hernia repair: Effect on biocompatibilty

Titanium and its alloys are used worldwide in surgery. The favorable characteristics that make this material desirable for implantation are corrosion resistance and biocompatibility. Concerning hernia repair, a mesh modification has been developed using titanium layering of a polypropylene mesh implant, which is said to lead to an improved biocompatibility compared to commercially available mesh materials. To analyze the pure effect of titanium coating, two different mesh structures were studied using a standardized animal model. The titanium-coated monofilamentous, large porous, and lightweight mesh made of polypropylene and coated with titanium (PP+T) was compared to a pure polypropylene mesh manufactured with a similar structure and amount of material serving as a control (PP). In Sprague-Dawley rats, mesh samples were placed in a subcutaneuous position. Then 56, 84, and 182 days after mesh implantation, three animals from each group were sacrificed for morphological observations (amount of inflammatory and connective tissue formation, percentages of proliferating and apoptotic cells, percentage of macrophages). Both mesh modifications investigated showed an overall good biocompatibility. Macroscopic clinical observation after implantation of up to 182 days was uneventful. The tissue response to the PP as well as to the PP+T mesh was characterized by a moderate inflammatory tissue reaction limited to the perifilamentary region as is known for low weight, large porous, and monofilamentous mesh structures. No significant improvement of biocompatibility was found when analyzing the effect of titanium coating compared to the pure polypropylene mesh structure.     

Influence of semi-recumbent position on intra-abdominal pressure as measured by bladder pressure

BACKGROUND: Intra-abdominal pressure (IAP) obtained by bladder pressure measurement is used to detect impending abdominal compartment syndrome (ACS), but, while it is recommended to use a supine position, the literature describes IAP measurement in varying positions. This study evaluated the impact of body position at differing head-of-bed (HOB) elevations on bladder pressure when planned to be used as a surrogate IAP measurement. MATERIALS AND METHODS: Forty-five trauma patients admitted to a surgical intensive care unit underwent bladder pressure measurements at 0, 15, 30, 45 degrees HOB position and 30 degrees HOB position plus 15 degrees of reverse Trendelenburg tilt; these measurements were performed in counterbalanced fashion and assessed by built-in angle indicators on the bed rails of each bed. Study participants were connected to an IAP monitoring kit via their indwelling Foley catheter. RESULTS: A total of 675 bladder pressure measurements were obtained with 135 measurements at each of five HOB elevations (0 degrees , 15 degrees , 30 degrees , 45 degrees , 30 degrees +15 degrees tilt). Statistically significant differences occurred between all HOB elevations. Statistically significance differences also occurred at different BMI statuses. CONCLUSIONS: Elevating HOB significantly increases bladder pressure measurement. Bladder pressure measurements in nonsupine positions may not provide valid interpretation for IAP, and more so in cases of increased body mass index.     

Sixty-month follow-up after endoscopic inguinal hernia repair with three types of mesh: a prospective randomized trial

Background  This prospective, clinical, randomized, double-blind study was intended to investigate the impact of the structure and the amount of polypropylene (PP) mesh used in laparoscopic transabdominal preperitoneal hernioplastic (TAPP) on physical function and life quality. Methods  180 male patients with primary inguinal hernia undergoing TAPP were randomized for using a heavyweight (108 g/m²), double-filament PP mesh (Prolene, 10 × 15 cm, group A, n = 60), a multifilament, heavyweight variant (116 g/m²) of PP mesh (Serapren, 10 × 15 cm, group B, n = 60), or a composite mesh (polyglactin and PP) (Vypro II, 10 × 15 cm, group C, n = 60). We compared in terms of complications (seromas, recurrence rate) and life quality (pain development, physical function). The development of life quality was documented according to the SF-36 Health Survey. The follow-up period was 60 months. Results  The recurrence rate (2.2% overall) during 60-month follow-up was not significantly different between the groups. Convalescence in group A was slower than in groups B and C: mean-term values of the visual scales for pain development were significantly (p < 0.05) higher, incapacity for work was 8.2 days longer, and urological adverse effects were stronger. The mean-term development of life quality was significantly lower in group A up to 12th week postoperatively. There were no significant differences between groups B and C. Beyond the 12th postinterventional week the differences diminished. Conclusions  The composite mesh does not provide an advantage concerning physical function or pain development in comparison to the multifilament, heavyweight, pure polypropylene mesh. Independently of which mesh was implanted 5% of patients are still suffering from discomfort after 5 years.     

The suturing concept for laparoscopic mesh fixation in ventral and incisional hernias: Preliminary results

Having found existing techniques for treatment of incisional hernias unsatisfactory, we developed a new laparoscopic approach with a Parietex Composite mesh. This study shows the preliminary results in order to analyze the validity of the concept on efficacy and safety. Three trocars are needed for this procedure. Non-reabsorbable sutures are mandatory for closure of large defects to avoid having to ultimately extrude the mesh. Ten to12 cardinal stitches are applied on the polyester side of the mesh. The mesh is anchored to the anterior abdominal wall by transabdominal non-reabsorbable sutures without the use of staples or tacks. One hundred twenty patients with ventral and incisional hernias were included in this study. Early and late complications are reported, showing lower rates of morbidity and no mortality. This technique is satisfactory on the technical front, and the results are as good, or better, than in other trials.     

An ambispective observational study in the safety and efficacy of posterior colporrhaphy with composite Vicryl-Prolene mesh

There is increasing evidence to show that the use of surgical meshes reduces recurrence rates of hernia repair and anterior vaginal wall prolapse. The aim of this study was to determine the safety and efficacy of posterior colporrhaphy with mesh in patients with posterior vaginal prolapse. An ambispective observational study involving 90 patients was conducted with retrospective chart review and prospective subjective and objective assessments at the end of a 1-year study period. Apart from 2 of 90 (2.2%) minor hematoma incidents, there was no other major perioperative morbidity. Prevalence of common prolapse complaints of vaginal lump sensation, constipation, defecation difficulty and dyspareunia all improved significantly postoperatively (p<0.001). Surgical correction was achieved in 27 of 31 (83.9%) at 6 months and beyond. There was no mesh infection but minor vaginal mesh protrusion was found in 7 of 90 (7.8%) patients at 6–12 weeks and 4 of 31 (12.9%) patients at 6 months and beyond. All these were treated easily with trimming without the need of mesh removal. We conclude that posterior colporrhaphy with mesh is effective in treating posterior vaginal prolapse in short term.Editorial Comment: This study reflects the authors experience in using a Vicryl-Prolene mesh, Vypro II, for treatment of rectocele in 90 patients. No serious operative or postoperative complications occurred. The most common minor complication was vaginal mesh protrusion, with a 9 of the 90 being found with this problem; all but 1 of these were resolved with a simple clinic procedure. In a group of 31 patients followed for at least 6 months, the authors note a 16% recurrence rate of rectocele. In a questionnaire given after the surgeries, comparing pre-op and post-op symptoms, 63–79% of the respondents felt improved, depending on the symptom. The authors feel that vaginal colporrhaphy with Vicryl-Prolene mesh will prove to be more efficacious than the existing popular approaches, including site-specific defect repair. Clearly, randomized controlled studies with longer follow-up comparing this method with other colporrhaphy techniques will be needed to validate this assumptionAn erratum to this article can be found at     

Transvaginal repair of genital prolapse: preliminary results of a new tension-free vaginal mesh (Prolift™ technique)—a case series multicentric study

Our goal was to report the preliminary results of a transvaginal mesh repair of genital prolapse using the Prolift™ system. This retrospective multicentric study includes 110 patients. All patients had a stage 3 (at the hymen) or stage 4 (beyond the hymen) prolapse. Total mesh was used in 59 patients (53.6%), an isolated anterior mesh in 22 patients (20%) and an isolated posterior mesh in 29 patients (26.4%). We report one bladder injury sutured at surgery and two haematomas requiring secondary surgical management. At 3 months, 106 patients were available for follow-up. Mesh exposure occurred in five patients (4.7%), two of them requiring a surgical management. Granuloma without exposure occurred in three patients (2.8%). Failure rate (recurrent prolapse even asymptomatic or low grade symptomatic prolapse) was 4.7%. According to the perioperative and immediate post-operative results, Prolift™ repair seems to be a safe technique to correct pelvic organ prolapse. Anatomical and functional results must be assessed with a long-term follow-up to confirm the effectiveness and safety of the procedure.     

Laparoscopic transabdominal preperitoneal approach to place a polypropylene mesh on the abdominal wall: an experimental swine model of a technique that can be used for incisional hernia repair

Background The placement of intraabdominal polypropylene mesh entails risks of adhesions and fistulas that can be avoided by preperitoneal placement.Methods This comparative, open, experimental, prospective, randomized, and transversal study randomized pigs into two groups of 11 each for intraperitoneal (IPOM) or preperitoneal (TAPP) polypropylene mesh placement by laparoscopy. Diagnostic laparoscopy and tissue en-bloc resection was performed 28 days postoperatively for histopathologic analysis.Results The following data were observed for the two study groups: surgical time (IPOM: 35.73 ± 4.22 min; TAPP: 58.09 ± 6.28 min; p = <0.0001); adhesions (IPOM: 81.81%; TAPP: 27.27%; p = 0.032), grade III for IPOM and grade II for TAPP (p = 0.001); and interloop adhesions (IPOM: 81.81%; TAPP: 9.09%; p = 0.003). No fistulas were found in either group. The TAPP procedure showed better integration of mesh, without lesion to abdominal organs. Two complications, occurred with IPOM, and one with TAPP (p = 1.0, not significant).Conclusions The perperitoneal technique requires more time, but has fewer adhesions and less intraabdominal inflammatory response. It is a feasible technique that may diminish risks in the laparoscopic treatment of incisional hernias with polypropylene mesh.     

脱细胞基质生物补片与聚丙烯补片在腹股沟嵌顿疝治疗中应用效果的前瞻性随机对照研究

目的探讨脱细胞基质生物补片与聚丙烯补片在腹股沟嵌顿疝治疗中的临床效果及安全性。 方法采用前瞻性随机分组研究2013年5月至2015年5月,四川省人民医院60例腹股沟嵌顿疝患者作为研究对象。试验组采用脱细胞基质生物补片修补,对照组采用聚丙烯补片修补。对比分析2组患者手术时间、术后住院时间2组患者的复发率、手术切口感染、慢性疼痛、异物感等发生率情况。 结果试验组与对照组在一般资料、手术时间、术后住院时间方面比较,差异均无统计学意义（P>0.05）。术后随访3年,2组患者复发率、切口感染率、慢性疼痛发生率比较,差异均无统计学意义（P>0.05）。对照组患者术后异物感发生率高于研究组,对照组的血清肿发生率低于试验组,差异均有统计学意义（P<0.05）。 结论脱细胞基质生物补片治疗腹股沟嵌顿疝可降低术后异物感发生率,但不会增加复发率,具有一定的临床应用价值。     

Influence of surface sub-micropattern on the adhesion of pioneer bacteria on metals

Abstract:  Most of the implantable medical devices are prone to infection caused by microorganisms that form biofilms. Pseudomonads are frequently used as model species for studying bacterial adhesion. The initial stages of biofilm formation are influenced by different factors including, among others, the chemistry of the surface, the roughness, and topography. The aim of this work was to assess the early stages of Pseudomonas fluorescens biofilm formation on sub-microstructured surfaces (SMS) that are in tune with bacterial size. Copper and gold were used as the substrata. It was concluded that SMS influenced bacterial length, alignment, and distribution, whereas the chemistry of the surfaces affected bacterial length and distribution. However, the effect of the SMS was the most significant. The shape of the bacterial colonies and the polymeric substances production were also influenced by SMS and the chemistry of the surface and both factors may be considered to reduce the susceptibility of a surface to biofilm formation.     

大网膜防止聚丙烯网片与腹腔脏器粘连的实验研究

目的:探讨大网膜防止聚丙烯网片与腹腔脏器粘连的作用及其丧失保护作用的原因。方法:1.动物实验:将雄性Wistar大鼠分为5组:(A)大网膜复盖组(n=15);(B)无大网膜复盖组(n=15);(C)大网膜切除组(n=15);(D)大网复盖 伤口葡萄球菌种植组(n=15);(E)大网膜切除组 伤口葡萄球菌种植组(n=15)。结果:D、E组动物术后死亡率明显高于A、B、C组(P<0.05)。术后1个月,D和E组粘连评分明显高于A、B、C组(P<0.05),术后2个月和3个月各组间粘连评分无显著性差别(P>0.05),但A和B组均为网膜与网片粘连,而D和E组则主要为肠管或肝脏参与粘连,C组为部分肠管或肝脏与网片粘连。结论:在无感染情况下大网膜具有防止腹腔脏器与网片粘连的作用,而感染后大网膜则失去保护作用,同样发生网片与腹腔脏器间的严重粘连。     

Preperitoneal mesh repair of spigelian hernias under local anesthesia: description and clinical evaluation of a new technique

We report on a new method for the repair of spigelian hernia, in which we combined the step-by-step local anesthesia and open preperitoneal mesh repair techniques. After initial infiltration of local anesthetics, we incised the attenuated fascia and slightly enlarged the fascial defect to facilitate easy return of hernial content into the abdominal cavity. We injected preperitoneally, in a radial fashion around the peritoneal sac, more saline solution, consisting of 1:200,000 epinephrine (g:g) and 1/3 bupivacain (v:v). We dissected the peritoneum away from the anterior abdominal wall to create a preperitoneal pocket of sufficient size. We spread open a 9 x 9-cm polypropylene mesh in the area, as if we were doing a GPRVS of Stoppa. We followed up our four patients for an average of 32 months. All four cases had an uneventful recovery and were discharged in an average of 3.5 days. They returned to normal daily activity on the 9th day after surgery. We suggest that the preperitoneal mesh repair of a spigelian hernia under local anesthesia is a simple and feasible technique with favorable early and late postoperative results and deserves further investigation in larger series.     

Prospective histologic evaluation of intra-abdominal prosthetics four months after implantation in a rabbit model

Background

Placement of an intraperitoneal prosthetic is required for laparoscopic ventral hernia repair. The biocompatibility of these prosthetics determines the host’s inflammatory response, scar plate formation, tissue ingrowth, and subsequent mesh performance, including prosthetic compliance and prevention of hernia recurrence. We evaluated the host response to intraperitoneal placement of several prosthetics currently used in clinical practice.

Methods

A 4-cm × 4-cm piece of mesh was implanted on intact peritoneum in New Zealand white rabbits. The mesh types included expanded polytetrafluoroethylene (ePTFE) (DualMesh^®), ePTFE and polypropylene (Composix^®, heavyweight polypropylene), polypropylene and oxidized regenerated cellulose (Proceed^®, midweight polypropylene), and polypropylene (Marlex^®, heavyweight polypropylene). At four months, standard hematoxylin and eosin and Milligan’s trichrome stains of the mesh-tissue interaction were analyzed by three observers blinded to the mesh types. Each specimen was evaluated for scar plate formation, inflammatory response, and tissue ingrowth. Each of these three categories was graded on a standard scale of 1–4 (1 = normal tissue and 4 = severe inflammatory response). The scores were analyzed using Wilcoxon rank sum test with p < 0.05 as significant.

Results

Ten samples of each mesh type were evaluated. There was no difference in tissue incorporation between the groups. The mean scar plate formation was greater in the heavyweight polypropylene meshes than for DualMesh (p = 0.04). With Proceed, the reduction in scar plate formation compared with that for Composix and Marlex approached statistical significance (p = 0.07). The mean number of inflammatory cells was greater around the ePTFE when compared with the midweight polypropylene (p = 0.02) but equal to the other meshes.

Conclusions

The four prosthetic materials evaluated in this study demonstrate comparable host biocompatibility as evidenced by the tissue ingrowth. Scar plate formation around DualMesh was significantly less than that around Composix and Marlex. Interestingly, more inflammatory cells were noted surrounding the DualMesh which was equal to that of the heavyweight meshes. Proceed, a midweight polypropylene mesh, has the potential for improved patient tolerance compared to heavyweight polypropylene meshes based on its favorable histologic findings.