A lightweight, partially absorbable mesh (Ultrapro) for endoscopic hernia repair: experimental biocompatibility results obtained with a porcine model.

BACKGROUND: A meticulous surgical technique, a mesh of adequate dimensions, and use of a mesh with good biocompatibility properties are decisively important for minimizing the development of recurrences after endoscopic hernia repair surgery. Mesh "shrinkage" is a function of the mesh's biocompatibility, that is, the properties of the mesh. Large-pore, lightweight polypropylene meshes possess the best biocompatibility, and the newly developed meshes meet these requirements. METHODS: Using a totally extraperitoneal technique in an experimental animal model, 10 domestic pigs were implanted with a lightweight, large-pore polypropylene mesh containing an absorbable component consisting of poliglecaprone (Ultrapro). After a period of 91 days, diagnostic laparoscopy followed by explantation of the specimens for macroscopic, histologic, and immunohistochemical evaluation was performed. RESULTS: The mean mesh shrinkage was a mere 1.9%. The partial volume of the inflammatory cells was a low 15.8%. The markers of cell turnover, namely Ki67 and the apoptosis index, were, at 5.8 and 2.1, respectively, also very low. The extracellular matrix showed a low value of transforming growth factor-beta (TGF-beta) (50.8). The mean value of collagen 1 was 136.9. CONCLUSIONS: As a result of its good biocompatibility and elastic properties, the lightweight, large-pore Ultrapo mesh showed only a very slight tendency to "shrink." This renders it extremely well suited for clinical use in hernia repair surgery, and its minimal shrinkage characteristic should help in achieving low complication and recurrence rates.

A lightweight polypropylene mesh (TiMesh) for laparoscopic intraperitoneal repair of abdominal wall hernias: comparison of biocompatibility with the DualMesh in an experimental study using the porcine model.

BACKGROUND: Despite numerous experimental studies, conducted most often with the open small-animal model, the ideal structure for a mesh with maximum biocompatibility in the intraabdominal region has yet to be found. To date, few experimental models have been concerned with the laparoscopic intraabdominal implantation of meshes. Numerous experimental and clinical studies appear to have identified expanded polytetrafluoroethylene (ePTFE), in the form of DualMesh, as the gold standard. Since publications have reported fistula formation and marked adhesions to be associated with the use of polypropylene meshes, only few studies have investigated meshes made of this material. It is known, however, that a reduction in the amount of material and an increase in pore size results in better mesh biocompatibility. METHODS: Six pigs each underwent laparoscopic intraabdominal placement of either a TiMesh or a DualMesh, both of which were prepared for implantation in standardized fashion. After 87 +/- 2 days, the pigs were killed, and postmortem laparoscopy was performed, followed by the removal of the tissue embedding the mesh for assessment of adhesions and shrinkage, and for histologic workup. The specimens were processed both histologically and immunohistochemically. RESULTS: In all but one case, the greater omentum adhered, usually over discrete areas, to the mesh. In every case the omentum was separable from the mesh surface only by sharp dissection. With the titanium-coated polypropylene meshes, the average total adhesion area was only 0.085, as compared with 0.25 for the GoreTex meshes (p = 0.055). The GoreTex meshes showed an average shrinkage to almost half of the original surface area (median, 0.435). The average shrinkage of the TiMesh, was to 0.18 of the original area (p = 0.006), which thus was significantly smaller. Determination of the partial volume of the inflammatory cells showed significantly lower median figures for the TiMesh (p = 0.009). Measurements of the proliferation marker Ki67 showed significantly higher values for ePTFE than for TiMesh (p = 0.011). The apoptosis index was significantly higher for the ePTFE membranes (p = 0.002). CONCLUSIONS: Titanium-coated polypropylene mesh (TiMesh) is clearly superior to the DualMesh in terms of biocompatibility, and is thus suitable for the laparoscopic intraperitoneal repair of abdominal wall and incisional hernias.

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.

In vivo studies comparing the biocompatibility of various polypropylene meshes and their handling properties during endoscopic total extraperitoneal (TEP) patchplasty: an experimental study in pigs.

BACKGROUND: Polypropylene (PP) meshes are currently being used in millions of operations for hernial repair. We tested several recently modified PP meshes to evaluate them in terms of their biocompatibility and handling characteristics during minimally invasive procedures. METHODS: Four different PP meshes (a heavyweight PP, Atrium; a lightweight PP incorporating absorbable polyglactic acid, Vypro II; a lightweight PP, Parietene; and a titanium-coated lightweight PP, Ti-Mesh Extralight), all implanted using the endoscopic total extrapreperitoneal (TEP) technique, were investigated in groups comprising 11 pigs each. After 94 +/- 5 days, the animals were autopsied and tissue samples were studied histologically, immunohistochemically, and electron-microscopically. RESULTS: Whereas endoscopic handling of the Vypro II mesh proved difficult, the already good properties of the Atrium mesh were significantly improved on by Parietene and the Ti-Mesh. Clear differences were also found in the shrinkage characteristics of the implant materials. In comparison with Atrium (12%), Vypro II mesh shrinkage was significantly greater (28%), whereas Parietene (7%) and Ti-Mesh (5%) incurred less shrinkage. With regard to the chronic inflammatory reaction, the titanium-coated mesh showed a significantly lower inflammatory activity (13.1% partial volume [%PV] vs 34.1%PV and 29.0%PV) than the lightweight meshes Vypro II and Parietene, but-with the exception of the monocytic (0.2 vs 9.1, 5.1, and 7.9) and B-lymphocytic reaction (1.1 vs 18.0, 11.7, and 12.2)-no significant difference was seen in comparison with Atrium. The various mediators in the extracellular matrix (matrix metalloproteinases 1 [MMP-1 transforming growth factor beta [TGF-beta], urokinase plasminogen activator [uPA], and type I collagen) tended to show the highest expression with Vypro II (13.6, 113.2, 132.7, and 139.5, respectively) and the lowest expression with Ti-Mesh (11.9, 68.5, 92.8, and 75.0, respectively). With regard to cell proliferation, Parietene and Ti-Mesh appeared to have slight advantages, but no differences were observed in the apoptotic rate. CONCLUSION: In our opinion, despite a reduction in material, Vipro II, on account of the inflammatory reaction, does not represent a true improvement over the meshes currently used for hernia repair. In comparison, the two lightweight PP patches are characterized by a more favorable foreign body reaction, with the titanium coating of the Ti-Mesh providing an additional advantage in terms of its biocompatibility.

Totally extraperitoneal repair of recurrent inguinal hernia.

BACKGROUND: A variety of procedures with substantial differences in results are employed to treat recurrent inguinal hernia. The advantages of totally extraperitoneal patch repair (TEP) are even more evident when it is applied to recurrent compared to primary hernias. To investigate the superiority of this method more closely, we reviewed our results obtained for recurrent inguinal hernias over a period of 2 years. METHODS: We performed a prospective single-center study using data obtained in consecutive patients with recurrent inguinal hernia who were operated on in 1997 and 1998. RESULTS: A total of 179 patients with recurrent inguinal hernia were recruited. Overall, 1329 patients with inguinal hernia were treated in the 2-year period, of whom 1270 underwent TEP. The percentage of recurrent hernias was 14%. The average age of the patients was 56 years. The follow-up rate was 87.5%, and the mean follow-up period was 2.3 years. The 154 patients who were followed up underwent a total of 225 hernia repairs, of which 181 were for recurrent hernias. The average operating time was 57 min. In 68% (104/154) of the patients, adhesions, adherent epigastric vessels, or cicatricial changes were found, which resulted in the inadvertant opening of the peritoneum in 26.3% of the patients. All the openings in the peritoneum were closed by endoscopic suturing. Intraoperative complications developed in 4 patients (2.3%), including one injury to the bladder and three cases of bleeding from side branches of the epigastric vessels. The conversion rate was 0%. The sole postoperative complication was treatment requiring hematomas in 7 patients, in 2 of whom reoperation became necessary. In both cases, a diffuse hemorrhage due to a preoperatively undiagnosed coagulation disorder was found. No cases of wound or patch infection were observed. In a patient undergoing both primary and recurrent hernia repair, displacement of a mesh led to a recurrence on the primary hernia side (recurrence rate, 0.4%; re-recurrence rate, 0%). CONCLUSIONS: Although for its definitive management, recurrent hernia requires a reliable operative technique, current data do not support the recommendation of any of the currently available procedures as the gold standard. In a representative patient population with recurrent hernia, we were able to demonstrate that TEP achieves very good results in terms of re-recurrence rate, intraoperative and postoperative complications, and rehabilitation. Prerequisites for the reliable and low-complication application of the method are a high level of standardization of the procedure and an advanced learning curve.

Totally extraperitoneal endoscopic inguinal hernia repair (TEP).

BACKGROUND: This report reviews our experience with 5,203 totally extraperitoneal (TEP) endoscopic hernia repairs performed in 3,868 patients over the 7.5-year period between May 1994 and December 2001, 34.5% of whom had bilateral hernias and 13% recurrent hernias. METHODS: We performed TEP as the method of choice in more than 92% of all the patients presenting with inguinal hernia, including those with incarcerated, strangulated, or inguinoscrotal hernias. After reduction of the hernial sac and appropriate dissection of the preperitoneal space, we placed a slit-free 10 x 15-cm polypropylene mesh without the use of staple fixation. RESULTS: Altogether, 29 recurrent hernias (0.6%) were observed, more than 50% of which occurred during the first 2 years after the technique was introduced (1.8%). During subsequent years, the recurrence rate settled to approximately 0.3%. Regarding intraoperative complications, we observed eight injuries to the bladder. At this writing, no bowel injuries or damage to iliac vessels has been seen. Postoperatively, we noted only a single case of mesh infection. In 14 cases (0.4%), postoperative hemorrhage necessitated either inguinal or endoscopic reoperation. As a further major complication, a small bowel obstruction caused by inadequate closure of a peritoneal lesion occurred in two patients (0.05%). The overall reoperation rate for the 3,868 patients was 0.6%. CONCLUSIONS: We consider TEP to be a procedure that carries an acceptably low complication rate, combining the advantages of minor access surgery and mesh reinforcement of the groin. This approach is associated with early postoperative return to usual activities and a very low recurrence rate.

Laparoscopic management of traumatic ruptures of the diaphragm.

INTRODUCTION: As a result of the relatively high frequency of high-speed accidents, diaphragmatic rupture is a diagnosis that is increasingly being established. Not all of these, usually multi-traumatized, patients are diagnosed as having diaphragmatic rupture immediately following the traumatic event--rather, an appreciable number of these injuries are not detected until some time later--often after a considerable delay. Most of the cases involve rupture of the left diaphragm, with most defects occurring in the region of the central tendon. METHODS: During the course of the second half of the year 1998, we operated on three patients with left diaphragmatic rupture. Two of these patients were treated immediately following traumatization, while the third case was a 10-year-old rupture originally misdiagnosed as a para-esophageal hernia. In all three cases, we were able to reduce the hernia and close the diaphragmatic defect laparoscopically. In the case of the two patients with a fresh rupture, the post-operative course was unremarkable, while in the patient with the missed rupture, a serous pleural effusion requiring drainage occurred on the left side. CONCLUSION: Overall, it would appear that in the case of an acute traumatic diaphragmatic rupture in particular, laparoscopic management, with its low level of traumatization and excellent access, offers a favorable alternative to conventional surgery. A point to be considered, however, is the fact that probably not every hospital will have the facilities for laparoscopic management available on a 24-h basis. In the case of longstanding ruptures, reduction of herniated bowel and treatment of the rupture will make considerable demands on the surgeon.

[Laparoscopic cholecystectomy with mini-instruments. Technique and initial experiences]. / Die laparoskopische Cholezystektomie mit Mini-Instrumentarium. Technik und erste Erfahrungen.

The aim of the present paper is to describe the development of a standardized technique of laparoscopic cholecystectomy using mini-instruments in order to demonstrate its feasibility with no increase in the risk of the patient. For this purpose, the prospective data of the first 60 patients that appeared suitable to undergo laparoscopic cholecystectomy with mini-instruments were recorded initially, 45 patients were operated on using a 10 mm, 30 degrees standard laparoscope inserted via the umbilicus, together with two mini-instruments and a standard instrument inserted under the right costal arch. The subsequent 15 interventions were performed using, in addition to a 10 mm standard trocar placed in the umbilicus to accommodate the 10 mm laparoscope, three subcostal employed mini-trocars. For the special surgical steps involved in intraoperative cholangiography, and the clipping of the cystic duct and cystic artery, a minilaparoscope was introduced through the epigastric port. Fifty-five of the patients were women, their average age was 47.6 years and the mean BMI 23.5. The sole intraoperative complication seen was bleeding from the liver that made necessary conversion to a 5 mm port to aspirate the coagulum. Conversion to a standard 5 mm instrument was also required in two cases of broken forceps and in one case with a thick-walled gallbladder in which the mini grasping forceps proved too weak. The mean operating time was 62.4 min, and no postoperative complications occurred. For elective laparoscopic cholecystectomy including intraoperative cholangiography in slim patients, the use of mini-instruments is not associated with any increased risk of complications, and the operating time is acceptable. However, the general use of mini-instruments cannot as yet be recommended because of the less-than-optimal properties of the mini-instruments and the reduced optical quality of the mini-laparoscopes.

[Technique of total extraperitoneal endoscopic hernioplasty of the inguinal canal]. / Technik der totalextraperitonealen endoskopischen Hernioplastik (TEP) der Leiste.

The current end stage in the development of endoscopic treatment of inguinal hernia involves the introduction of a patch into the extraperitoneal space. This may be done via a transabdominal approach (TAPP) or via a total extraperitoneal approach (TEP). The present article describes the TEP technique in detail. In addition to dealing with the ideal case, the authors also discuss the procedure in relation to all know forms of hernia. Furthermore, they provide the reader with suggestions on how to deal with intraoperative technical problems and how to avoid recurrences.