A comparative study of adhesion formation and abdominal wall ingrowth after laparoscopic ventral hernia repair in a porcine model using multiple types of mesh

Background The ideal mesh for laparoscopic ventral hernia repair is not yet identified.Methods We laparoscopically placed polypropylene (PPM), expanded polytetrafluoroethylene (ePTFE), and polyester with antiadhesive collagen layer (PCO) in eight pigs using sutures and tacks for fixation. After 28-day survival, we compared adhesion formation, fibrous ingrowth, and shrinkage among the types of mesh.Results Mean area of adhesions to PCO (8.25%) was less than that to ePTFE (57.14%, p < 0.001) or PPM (79.38%, p < 0.001). Adhesions peel strength was less for PCO (2.3 N) than for PPM (16.1 N, p < 0.001) or ePTFE (8.8 N, p = 0.02). Peel strength of mesh from the abdominal wall was less for ePTFE (1.3 N/cm of mesh width) than for PCO (2.8 N/cm, p = 0.001) or PPM (2.1 N/cm, p = 0.05). ePTFE area (94.4 cm²) was less than that for PCO (118.6 cm², p < 0.001) or PPM (140.7 cm², p < 0.02).Conclusion PCO had fewer and less severe adhesions than ePTFE or PPM while facilitating excellent ingrowth of the adjacent parietal tissue.     

Suture versus staple for fixation of mesh in incisional hernia repair

The incidence of incisional hernia has been reported to be between 11 and 20% in patients post laparotomy and carries the risk of pain, incarceration and strangulation. Prosthetic mesh for incisional hernia repair has been shown to be superior to suture repair. The recurrence rate of primary mesh repair of incisional hernias has been reported to be as high as 38%. This experimental study in euthanised rats aims to compare the fixation strength of mesh using sutures and surgical staples. Forty euthanised adult male Sprague–Dawley rats were used for midline laparotomy incisions and repair of the abdominal wall carried out using polypropylene mesh anchored using either skin staples or Prolene sutures. An intra‐abdominal expander device was inserted into the abdomen and inflated to measure ‘burst pressure’. Pressure changes and surgical time were recorded. There was no statistically significant difference (P = 0.83) in the pressure required to disrupt the mesh fixation between the two groups, 101 ± 12 mmHg in the suture group versus 102 ± 14 mmHg in the staple group. Staple fixation was 9.7 times faster compared with suture fixation, 291 ± 42 s for suture versus 30 ± 8 s for staples (P < 0.001) (power = 94%). The immediate strength of fixation is equal using both sutures and staples, however staple fixation is faster. Mesh migration due to inadequate fixation using either method is unlikely to cause early failure, however suture and staple ‘cut out’ during early movement may explain this.     

关节镜下"8"字缝线与网兜缝线固定治疗前十字韧带胫骨止点撕脱骨折

目的探讨关节镜下"8"字缝线与网兜缝线固定治疗前十字韧带(anterior cruciate ligament,ACL)胫骨止点撕脱骨折的早期临床疗效。方法回顾性分析2013年8月至2016年11月收治的37例ACL胫骨止点撕脱骨折并获得完整随访的患者,所有患者骨骺均已闭合。Meyers-McKeever-Zaricznyj骨折分型:Ⅱ型10例,Ⅲ型22例,Ⅳ型5例。固定方式采用"8"字缝线法25例,男17例,女8例,年龄(18.91±9.34)岁(范围14~36岁),以两根2号高强度缝线交叉成"8"字经胫骨骨道拉出固定骨折块;采用网兜缝线固定12例,男8例,女4例,年龄(19.63±7.85)岁(范围15~33岁),以三根2号高强度缝线编织成网兜经胫骨骨道拉出固定骨折块。手术前后采用Lysholm及国际膝关节评分委员会(International Knee Documentation Committee,IKDC)评分评价膝关节功能,通过Lachman试验及Pivot-shift试验评价膝关节稳定性,并记录手术时间、膝关节活动度及伸膝阻滞情况。结果"8"字缝线组随访(16.35±5.27)个月(范围10~22个月),网兜缝线组(14.06±7.18)个月(范围10~21个月)。末次随访时,"8"字缝线组的Lysholm、IKDC评分分别为(95.86±5.74)分、(90.53±4.61)分,网兜缝线组分别为(96.53±3.17)分、(92.15±5.54)分,两组差异无统计学意义(t=0.723,P=0.462;t=1.018,P=0.279);"8"字缝线组Lachman试验及Pivot-shift试验阴性率均为92%(23/25),网兜缝线组均为100%(12/12),两组差异无统计学意义(χ^2=0.904,P=0.265);网兜缝线组手术时间为(61.8±6.3)min,较"8"字缝线组的(43.5±5.9)min长,差异有统计学意义(t=2.714,P=0.025);"8"字缝线组伸膝受限(5°或以上伸膝受限)发生率为16%(4/25),网兜缝线组为0,两组差异有统计学意义(χ^2=0.450,P=0.032)。结论关节镜下"8"字缝线固定与网兜缝线固定技术治疗ACL胫骨止点撕脱骨折均可获得良好的早期膝关节功能和稳定性。网兜缝线固定技术可完整复位骨折块,术后伸膝阻滞发生率低,在治疗旋转Ⅲ型和粉碎Ⅳ型骨折中可能更具有优势;但有技术要求高、手术时间长的缺点。     

Comparison of Adhesive Properties of Five Different Prosthetic Materials Used in Hernioplasty

This experimental study was designed to assess and to compare intra-abdominal adhesions following the use of five commercially available prosthetic mesh grafts in the repair if abdominal wall defects. Sixty Wistar albino rats were randomly divided into six groups (n = 10). A 2 × 1 cm defect at abdominal wall was created and defects were closed either primarily or with one of the following prosthetic mesh grafts: monofilament polypropylene, polytetrafluoroethylene, sodium hyaluronate/carboxymethylcellulose-coated polypropylene, polypropylene/polyglactin 910 composite, or resorbable hydrophilic collagen-coated multifiber polyester. The severity of adhesions was graded, tensile strengths of adhesions were measured, and histopathological grades of inflammation and fibrosis were evaluated. Polypropylene mesh resulted in more adhesion formation in comparison to primary repair and other grafts used in this study, except polypropylene/polyglactin 910 composite mesh. In addition, the highest tensile strength of omental adhesions was detected in the polypropylene group (χ² = 26.249; p =. 0001). Polyester composite mesh caused the least adhesion formation among the groups. Sodium hyaluronate/carboxymethylcellulose-coated polypropylene and polyester composite meshes revealed the highest fibrosis scores (χ² = 50.776; p =. 0001). The highest inflammatory activity was detected in the polytetrafluoroethylene mesh group (χ² = 16.564; p =. 005). Thus, sodium hyaluronate/carboxymethylcellulose-coated polypropylene and polytetrafluoroethylene meshes following polyester composite mesh were the minimal adhesion-forming grafts in this study. Disadvantages of the polytetrafluoroethylene mesh were lower fibrotic activity and higher inflammatory reaction to the graft.     

Prevention of adhesion formation to polypropylene mesh by collagen coating: A randomized controlled study in a rat model of ventral hernia repair

Introduction In laparoscopic incisional hernia repair with intraperitoneal mesh, concern exists about the development of adhesions between bowel and mesh, predisposing to intestinal obstruction and enterocutaneous fistulas. The aim of this study was to assess whether the addition of a collagen coating on the visceral side of a polypropylene mesh can prevent adhesion formation to the mesh.Method In 58 rats, a defect in the muscular abdominal wall was created, and a mesh was fixed intraperitoneally to cover the defect. Rats were divided in two groups; polypropylene mesh (control group) and polypropylene mesh with collagen coating (Parieten mesh). Seven and 30 days postoperatively, adhesions and amount and strength of mesh incorporation were assessed. Wound healing was studied by microscopy.Results With Parieten mesh, the mesh surface covered by adhesions was reduced after 30 days (42% vs 69%, p = 0.01), but infection rate was increased after both 7 (p = 0.001) and 30 days (p = 0.03), compared to the polypropylene group with no mesh infections. If animals with mesh infection were excluded in the analysis, the mesh surface covered by adhesions was reduced after 7 days (21% vs 76%, p = 0.02), as well as after 30 days (21 vs 69%, p < 0.001). Percentage of mesh incorporation was comparable in both groups. Mean tensile strength of mesh incorporation after 30 days was higher with Parieten mesh.Conclusion Although the coated Parieten mesh was more susceptible to mesh infection in the current model, a significant reduction of adhesion formation was still seen with the Parieten mesh after 30 days, with comparable mesh incorporation in the abdominal wall.     

Assessment of adhesion formation to intra-abdominal polypropylene mesh and polytetrafluoroethylene mesh

BACKGROUND: The development of intra-abdominal adhesions, bowel obstruction, and enterocutaneous fistulas are potentially severe complications related to the intraperitoneal placement of prosthetic biomaterials. The purpose of this study was to determine the natural history of adhesion formation to polypropylene mesh and two types of polytetrafluoroethylene (ePTFE) mesh when placed intraperitoneally in a rabbit model that simulates laparoscopic ventral hernia repair. MATERIALS AND METHODS: Thirty New Zealand white rabbits were used for this study. A 10-cm midline incision was performed for intra-abdominal access and a 2 cm x 2 cm piece of mesh (n = 60) was sewn to an intact peritoneum on each side of the midline. Two types of ePTFE mesh (Dual Mesh and modified Dual Mesh, W.L. Gore & Assoc., Flagstaff, AZ) and polypropylene mesh were compared. The rate of adhesion formation was evaluated by direct visualization using microlaparoscopy (2-mm endoscope/trocar) at 7 days, 3 weeks, 9 weeks, and 16 weeks after mesh implantation. Adhesions to the prosthetic mesh were scored for extent (%) using the Modified Diamond Scale (0 = 0%, 1 50%). At necropsy the mesh was excised en bloc with the anterior abdominal wall for histological evaluation of mesothelial layer growth. RESULTS: The mean adhesion score for the polypropylene mesh was significantly greater (P < 0.05) than Dual Mesh at 9 weeks and 16 weeks and modified Dual Mesh at 7 days, 9 weeks, and 16 weeks. Fifty-five percent (n = 11) of the polypropylene mesh had adhesions to small intestine or omentum at necropsy compared to 30% (n = 6) of the Dual Mesh and 20% (n = 4) of the modified Dual Mesh. There was a significantly greater percentage (P < 0.003) of ePTFE mesh mesothelialized at explant (modified Dual Mesh 44.2%; Dual Mesh 55.8%) compared to the polypropylene mesh (12.9%). CONCLUSIONS: Serial microlaparoscopic evaluation of intraperitoneally implanted polypropylene mesh and ePTFE mesh in a rabbit model revealed a progression of adhesions to polypropylene mesh over a 16 week period. The pore size of mesh is critical in the development and maintenance of abdominal adhesions and tissue ingrowth. The macroporous polypropylene mesh promoted adhesion formation, while the microporous nature of the visceral side of the ePTFE served as a barrier to adhesions.     

Tissue ingrowth and bowel adhesion formation in an animal comparative study: polypropylene versus Proceed versus Parietex Composite

Background The optimal prosthesis for laparoscopic ventral hernia repair would combine excellent parietal surface tissue ingrowth with minimal visceral surface adhesiveness. Currently, few data are available from randomized trials comparing the commercially available prostheses. Methods In a pig model designed to incite adhesions, three 10 × 15-cm pieces of mesh (Proceed, Parietex Composite [PCO], and polypropylene [PPM]) were randomly positioned intraperitoneally in each of 10 animals using sutures and tack fixation. After a 28-day survival, the amount of shrinkage, the area and peel strength of visceral adhesions, the peak peel strength, the work required to separate mesh from the abdominal wall, and a coefficient representing the adhesiveness of tissue ingrowth were averaged for each type of mesh and then compared with the averages for the other prostheses. The histologic appearance of each prosthesis was documented. Results Proceed had more shrinkage (99.6 cm²) than PCO (105.8 cm²) or PPM (112 cm²), although the difference was not statistically significant. The mean area of adhesions to PCO (11%) was significantly less than for Proceed (48%; p < 0.008) or PPM (46%; p < 0.008). Adhesion peel strength was significantly less for PCO (5.9 N) than for Proceed (12.1 N; p < 0.02) or PPM (12.9 N; p < 0.02). According to a filmy-to-dense scale of 1 to 5, adhesions were more filmy with PCO (1.7) than with PPM (2.9) or Proceed (3.7) (p < 0.007). Peak peel strength from the abdominal wall was significantly higher for PCO (17.2 N) than for Proceed (10.7 N) or PPM (10 N; p < 0.002). The histology of each prosthesis showed a neoperitoneum only with PCO. Conclusions With less shrinkage, fewer and less dense adhesions to the viscera, and significantly stronger abdominal wall adherence and tissue ingrowth at 28 days in this animal study, PCO was superior to both Proceed and PPM in all categories. Furthermore, PCO demonstrated all the favorable qualities needed in an optimal prosthesis for laparoscopic ventral hernia repair, including the rapid development of a neoperitoneum.     

Experimental Study of the Effect of Different Meshes on Bacterial Translocation

Implantation of intraabdominal biomaterials promotes bacterial translocation (BT). In this study we planned to determine the effect of different types of mesh on the induction of BT. Swiss albino mice were divided into four groups: control, polypropylene (PP), polyglactin 910 (PG), and dura mater (DM). At hour 0, an abdominal wall defect was created in all animals. In the control group the defect was closed primarily. PP, PG, and DM meshes were used to repair the defects such that the intestines were in contact with the mesh in the remaining three groups. BT was evaluated 4, 24, and 48 hours later. At 4 hours total BT increased in the PP group compared with that in the control (p= 0.0321) and DM (p= 0.0098) groups. At 24 hours the PG group had increased BT compared with the controls (p= 0.0392) and the DM group (p= 0.0274), whereas the PP group had increased BT compared with the DM group only (p= 0.0477). At 48 hours both PG and PP groups had increased BT compared with controls (p= 0.0431 and p= 0.0001, respectively); the PP group had also increased BT compared to the DM group (p= 0.001) and the PG group (p= 0.017). In the control, DM, and PP groups there was no intragroup statistical difference. In the PG group there was a significant increase in BT at 24 hours compared to that at 4 hours (p= 0.0274). Prosthetic meshes led to increased BT compared to that with the DM mesh. This effect might be attributed to the different organic and physical properties of the meshes.     

Totally extraperitoneal inguinal hernioplasty with titanium-coated lightweight polypropylene mesh: early results

Background This prospective study of a new titanium-coated low-weight polypropylene (PP) mesh (16 g PP/m²) was designed to investigate the clinical efficacy and safety of totally extraperitoneal endoscopic hernioplasty (TEP). Methods In this study, 400 patients (average age, 53.5 years; range, 19 – 80 years) with a total of 588 inguinal hernias underwent surgery with the TEP technique between September 2002 and October 2003. Of these patients, 12.4% had experienced recurrent hernias after open suture herniotomy. In 92% of the cases (368 patients with 540 hernias), a lightweight (16 g PP/m²) titanium-coated polypropylene mesh was implanted without fixation, and in 8% (32 patients with 48 hernias) an identical medium-weight (35 g PP/m²) mesh was implanted. The first follow-up examination was scheduled for postoperative week 6. Results In the lightweight mesh group, the mean group, operating time per patient was 61 min, corresponding to a calculated time per hernia of 41 min. Two intraoperative major complications occurred: an injury to the cecum and an injury to the bladder. In 12 cases (2%), bleeding from epigastric, testicular, or pubic bone vessels was observed. No injuries to pelvic vessels were seen. One patient was underwent an endoscopic revision to deal with an anticoagulation-related bleed. The mortality rate was 0%. In 12 patients, postoperative hematomas developed. One preperitoneal lipoma had to be extirpated. No infections of the mesh occurred. The median follow-up period for 371 patients (92.3%) was 7.2 weeks (range, 4–14 weeks). These 343 patients (with 504 hernias) had been provided with a lightweight titanium-coated polypropylene mesh (16 g PP/m²) (follow-up rate, 93.2%). Of these patients, 3.5% reported persistent ingunial pain, 1.7% described a sensation of rigidity in the region of the groin, and 3.2% reported dysesthesia. The early recurrence rate was 0.2%. Conclusions The TEP procedure can be performed safely and effectively with the appreciably material-reduced and titanium-coated polypropylene mesh without the need for fixation of the implant. The low early recurrence rate of 0.2% is evidence that the posterior wall of the inguinal canal is adequately augmented. The question whether the material reduction and the titanium coating of the mesh may bring about a reduction in postoperative chronic pain and the sensation of rigidity in the inguinal area via an improvement in biocompatibility must await the results of the scheduled follow-up examination 1 year after the surgical procedure.     

改良式腹腔镜腹膜外补片植入法疝修补术

目的探讨改进式腹腔镜腹膜外补片植入法腹股沟疝修补术的可行性及临床意义.方法回顾性分析我院2002年6月～2004年10月13例腹股沟疝进行的腹腔镜下经腹腔腹膜外补片植入法联合腹膜缝合覆盖修补术的临床资料.其中腹股沟斜疝9例,直疝4例;其中复发疝1例;右侧8例,左侧4例,双侧1例.结果手术均获成功,单侧手术时间35～85 min,平均50 min,无一例中转开腹,无术后并发症,术后平均住院时间2 d,13例随访1～28个月,平均12个月,无一例复发.结论腹腔镜下经腹腔途径腹膜外补片植入法联合腹膜缝合覆盖术是一种安全、可靠、疗效显著的腹股沟疝修补方法,具有手术操作简单、创伤小、术后疼痛轻、恢复快等优点,可以代替开放手术,值得推广应用.     

Cost analysis of incisional hernia repair by suture or mesh

The objective was to make a cost analysis of incisional hernia repair by suture repair or prosthetic mesh repair. The study included 44 patients who underwent hernia repair between 1991 and 2000. The rate of recurrent incisional hernia after more than 1 year with associated costs was registered. In 1996, the technique of incisional hernia repair was changed from suture repair to mesh repair. With a mesh repair, zero out of 19 patients presented with a recurrence at follow-up, and with suture repair, five out of 13 had a recurrence (P<0.01). The duration of anaesthetic and operation was longer, but stay in the surgical ward, and sick leave was shorter for patients with a mesh repair than for those with a suture repair. For working patients, costs in the operating theatre were 4,095 Swedish kronor (SEK) higher with a mesh repair, and the costs for surgical ward, sick leave, and examination were 10,129 SEK lower than with a suture repair. Thus, with a mesh repair, the total costs were 6,034 SEK lower than with a suture repair. For retired patients, the total costs with a mesh repair were 1,898 SEK lower than with a suture repair. We conclude that in this setting, mesh repair of incisional hernias produced lower costs than suture repair.     

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.     

Laparoscopic inguinal hernia repair without mesh fixation, early results of a large randomised clinical trial

Background A new persistent groin pain is reported by a significant number of patients following laparoscopic totally extraperitoneal hernia repair (TEP). Mesh fixation has been implicated as a possible cause, but is widely considered essential for mesh stabilization and early recurrence prevention. This study investigates whether any association exists between mesh fixation by metal tacks and the incidence of new groin pain or early hernia recurrence. Methods A prospective multicenter double-blinded randomised trial was conducted between December 2004 and January 2006. Standardized TEP repair was performed with a rectangular 10 × 15cm polypropylene mesh. Hernia were randomized to either mesh fixation by metal tacks or left entirely unfixated. Clinical review by physical examination was performed by a separate blinded surgeon after a minimum of six months, with another review planned after two years. The incidence of new groin pain and recurrence were compared. Results Five hundred herniae in 360 patients were entered into the study. At the first wave of clinical follow-up (median eight, range 6–13 postoperative months) a new pain was reported by 38 versus 23% (p = 0.003), occurring at least once a week in 22 versus 15% (p = 0.049), or several times per week in 16 versus 8% (p = 0.009) for fixated versus unfixated repairs, respectively. Patients with bilateral repairs were five times more likely to report the unfixated side being more comfortable (p = 0.006). There was one recurrence in the fixated group (1/247) whilst none have yet occurred in the unfixated group. Fixation increased operative costs by approximately 375 AUD. Conclusion Mesh fixation in TEP is associated with increased operative cost and chronic pain but no difference in the risk of hernia recurrence at six months was observed.     

Primary incisional hernia repair with or without polypropylene mesh: a report on 384 patients with 5-year follow-up

Background and aim Several studies have claimed that mesh repair of incisional hernia lowers recurrence rates when compared to suture repair. We investigated the relative effectiveness of mesh and suture repair in a large homogeneous cohort of patients with primary incisional hernia.Patients and methods In a retrospective single-centre cohort study, a total of 446 consecutive patients were identified, of whom 86% could be followed up. Mean length of follow-up was 5 years. In 79 patients (22%), we implanted a mesh, usually polypropylene (Prolene).Results Compared to suture repair, mesh repair prolonged operating time by over 30 min and caused seroma in 12.7% of the patients (p<0.001). Only 4 of the 79 patients with mesh repair developed recurrence, compared to 55 of the 305 patients with suture repair (5 vs 18%, p=0.02 by log-rank test). In multivariate Cox regression, recurrence rates were fourfold higher after suture than after mesh repair (p=0.02). Interestingly, old age was associated with a decreased susceptibility for recurrence (p=0.01).Conclusion Our data confirms the long-term effectiveness of mesh repair under routine conditions. Suture repair should be restricted to small hernias in patients free of known risk factors.     

Inhibition of Intra-Abdominal Adhesions: A Comparison of Hemaseel APR and Cryoprecipitate Fibrin Glue

Our previous studies demonstrated fibrin glue (FG) prepared from cryoprecipitate (cryo) inhibits intra-abdominal adhesions in rats. A new FG, Hemaseel APR, is Food and Drug Administration (FDA) approved for hemostasis during cardiac surgery and splenic trauma. This study was undertaken to determine if Hemaseel FG prevents intra-abdominal adhesions, and to compare it to cryo FG. Forty-five rats underwent laparotomy. Bilateral peritoneal-muscular defects were created. Polypropylene mesh was sewn into each defect with a running silk suture. The bowel was abraded with gauze. The rats were then randomized to mesh covered with Hemaseel FG, cryo FG, or control. On postoperative day 7, the severity of adhesions were graded by percentage of mesh covered by adhesion (0-100%) and degree of adhesion (0-3). The mean percentage of mesh covered by adhesion was 9% for Hemaseel FG, 43% for cryo FG (p = .005), and 65% for the controls (p &lt; .0001). The mean density adhesion score was 0.5 for Hemaseel FG, 1.2 for cryo FG (p = .04), and 2.1 for the controls (p &lt; .0001). In the Hemaseel FG group, 77% of patches had no adhesions, compared with 37% in the cryo FG group (p = .004) and 13% in the controls (p &lt; .0001). Thus, Hemaseel FG significantly decreases intra-abdominal adhesions, and is more effective than cryo FG.     

Suture anchor versus screw fixation for greater tuberosity fractures of the humerus—a biomechanical study

Suture anchors and screws are commonly used for fixation of humeral greater tuberosity (GT) fractures in either arthroscopic or open surgeries, but no biomechanical studies have been performed to compare the strength of fixation constructs using these two implants. This cadaveric study aimed to compare the biomechanical strength of three different fixation constructs in the management of GT fractures: Double‐Row Suture Anchor Fixation (DR); Suture‐Bridge Technique using suture anchors and knotless suture anchors (SB); and Two‐Screw Fixation (TS). The experimental procedure was designed to assess fracture displacement after cyclic loading, failure load, and failure mode of the fixation construct. Significant differences were found among the SB (321 N), DR (263 N), and TS (187 N) groups (SB > DR > TS, p < 0.05) in the mean force of cyclic loading to create 3 mm displacement. Regarding the mean force of cyclic loading to create 5 mm displacement and ultimate failure load, no significant difference was found between the DR (370 N, 480 N) and SB (399 N, 493 N) groups, but both groups achieved superior results compared with the TS group (249 N, 340 N) (p < 0.05). The results suggested that the suture anchor constructs would be stronger than the fixation construct using screws for the humeral GT fracture. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:423–428, 2012     

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.     

Laparoscopic inguinal hernia repair using an anatomically contoured three-dimensional mesh

Background: Laparoscopic inguinal hernia repair frequently is performed with mechanical fixation of a flat polypropylene mesh. Mechanical fixation is associated with pain syndromes, and mesh migration may occur without fixation of flat prostheses. An anatomically contoured mesh (3D Max; Davol, Cranston, RI, USA) using no or minimal fixation would avoid these problems. Methods: A retrospective case study reviewed 212 transabdominal preperitoneal herniaplasties with 11 × 16-cm 3D Max mesh in 146 patients. Fixation with three helical tacks at the most was used early or with very large defects. Results: Fixation was used in 19% of the cases, but only for 1 of the last 98 patients. As reported, 94% of the patients returned to normal activities by 3 weeks, 97% returned to unrestricted sports by 6 weeks, and 92% complete recovery from surgery by 9 weeks. Fixation or bilateral repair did not alter recovery. Four patients had minor pain or numbness. Symptomatic recurrence was 0%. One asymptomatic indirect recurrence was noted on examination, during a mean follow-up period of 23 months, yielding a 0.55% hernia rate and a 0.42% patient-year recurrence risk. Conclusions: An anatomically contoured mesh for transabdominal preperitoneal hernia repair often requires no fixation, with minimal risk of neuropathy and less than a 0.5% patient-year recurrence rate. Recovery is excellent even with bilateral repair or some fixation. Financial support for this study was provided by Davol, Inc., Cranst, USA     

Comparison of adhesion formation to intra-abdominal mesh after laparoscopic adhesiolysis in the New Zealand White rabbit

The purpose of this study was to investigate the effects of early adhesiolysis on long-term adhesion formation after the intraperitoneal implantation of polypropylene (PP) mesh and expanded polytetrafluoroethylene (ePTFE) mesh in a rabbit model. Through a small midline laparotomy a 2 x 2-cm piece of mesh (n = 80) was sewn to an intact peritoneum on each side of a midline incision in 40 New Zealand White rabbits. Two types of ePTFE mesh [Dual Mesh (Dual) and modified Dual Mesh (C-Type), W.L. Gore and Associates, Flagstaff, AZ] and PP mesh (Marlex, C.R. Bard, Murray Hill, NJ) were compared. In 10 rabbits (n = 20) a laparoscopic adhesiolysis (LapA) was performed at one week. Mesh adhesions were scored using a modified Diamond scale (0, 0%; 1, 1-25%; 2, 26-50%; and 3, > 50%) at 1, 3, 9, and 16 weeks by serial microlaparoscopic (2 mm) examinations. After recording the final adhesion score at 16 weeks the prosthetic biomaterials were excised en bloc with the anterior abdominal wall for histologic evaluation of mesothelial layer growth (%) on the visceral surface of the mesh. Statistical differences (P value < 0.05) were measured by chi-square and Wilcoxon signed rank tests. There were no statistical differences in mean adhesion scores at adhesiolysis at 7 days. The mean adhesion scores in the groups undergoing laparoscopic adhesiolysis was statistically less (P < 0.05) for PP and both ePTFE meshes at 3-, 9-, and 16-week intervals compared with those not undergoing adhesiolysis. The percentage of mesothelialization on the visceral surface of the mesh was not statistically different between the adhesiolysis and control groups for any of the prosthetic biomaterials. Laparoscopic adhesiolysis at one week minimizes subsequent adhesion formation to PP and ePTFE mesh over a 4-month follow-up. Adhesion formation within the first 7 days after mesh implantation appears to determine the long-term adhesion score. Eliminating adhesions to mesh by mechanical or other means during this critical time may control adhesions to the mesh and subsequent mesh-related complications.     

Five-year outcome of laparoscopic and Lichtenstein hernioplasties

Background: Laparoscopic hernia repair has been proved superior to open repairs in terms of short-term results, but long-term results of laparoscopic and open mesh repairs have been lacking until recently. Methods: A total of 123 patients were randomly allocated to two treatment groups comparing laparoscopic and Lichtenstein hernioplasties in three separate trials. The first and second trials compared small and large mesh used in transabdominal preperitoneal repairs, and the third study compared totally extraperitoneal hernioplasty with the Lichtenstein operation. A 5-year follow-up visit was scheduled to assess recurrencies, symptoms, and patient satisfaction. Results: For the follow up evaluation, 121 (98.4%) of the patients were reached. There were five hernia recurrences in the laparoscopic group (small mesh) and two in the Lichtenstein group (difference, 5%; 95% confidence interval, –4–13%; p = 0.3). One patient who underwent the transabdominal preperitoneal polypropylene procedure underwent reoperation 3 years later because of dense small bowel adhesions at the inguinal surgical site. Chronic groin pain was more common after open operation (0 vs 4) patients (difference 7%; confidence interval, –0.4–16%; p = 0.04). Ten patients (16%) in the laparoscopic group and 12 (20%) in the open group reported discomfort or pain at the surgical site. Conclusions: Both laparoscopic and Lichtenstein hernioplasties have a low risk for hernia recurrence if proper mesh size is used. The patients who undergo hernioplasty with open mesh hernioplasty seem to experience chronic symptoms and pain more often than those managed with the laparoscopic procedure.