Incisional hernia repair by synthetic mesh prosthesis in patients with inflammatory bowel disease: a comparative analysis.

BACKGROUND: Patients with inflammatory bowel disease (IBD) have a high-life time risk undergoing abdominal surgery and are prone to develop incisional hernias (IH) in the postoperative course. Therefore, we investigated the role of IBD as perioperative risk factor in open ventral hernia repair (OVHR) as well as the impact of IBD on hernia recurrence during postoperative follow-up. METHODS: The postoperative course of 223 patients (Non-IBD (n = 199) and IBD (n = 34)) who underwent OVHR were compared by means of extensive group comparisons and binary logistic regressions. Hernia recurrence was investigated in the IBD group according to the Kaplan-Meier method and risk factors for recurrence determined by Cox regressions. RESULTS: General complications (≥ Clavien-Dindo I) occurred in 30.9% (72/233) and major complications (≥ Clavien-Dindo IIIb) in 7.7% (18/233) of the overall cohort with IBD being the single independent risk-factor for major complications (OR = 4.2, p = 0.007). Further, IBD patients displayed a recurrence rate of 26.5% (9/34) after a median follow-up of 36 months. Multivariable analysis revealed higher rates of recurrence in patients with ulcerative colitis (UC, 8/15, HR = 11.7) compared to patients with Crohn's disease (CD, 1/19, HR = 1.0, p = 0.021). CONCLUSION: IBD is a significant risk factor for major postoperative morbidity after OVHR. In addition, individuals with IBD show high rates of hernia recurrence over time with UC patients being more prone to recurrence than patients with CD.

Incisional Hernia Repair of Medium- and Large-Sized Defects: Laparoscopic IPOM Versus Open SUBLAY Technique.

Background: Small incisional hernias can be repaired laparoscopically with low morbidity and reasonable recurrence rates. The aim of this study was to compare laparoscopic with open technique in medium- and large-sized defects regarding postoperative complications and recurrence rates. Methods: Between 2012 and 2016, 102 patients with medium- or large-sized defects according to EHS classification underwent incisional hernia repair. Patients' characteristics, hernia size and postoperative complications were prospectively recorded. In October 2016, eligible patients were assessed for recurrence. Results: About 31 patients underwent laparoscopic IPOM and 71 patients open SUBLAY repair. Morbidity rate was significantly lower in IPOM group than in SUBLAY group (19% versus 41%; p = .028). Postoperative complications according to Clavien-Dindo classification were significantly lower in the IPOM group (p = .021). Duration of surgery (88 versus 114 min; p = .009) and length of hospital stay (five versus eight days; p < .001) were significantly shorter for IPOM than for SUBLAY. 71 patients were available for follow-up. Recurrence rates showed no significant difference between study groups (13% versus 7%, p = .508). Conclusions: Laparoscopic repair in medium- and large-sized defects is a feasible and safe approach. IPOM compared to SUBLAY significantly reduces postoperative complications and hospital stay; recurrence rates are comparable.

AK03, a new recombinant fibrinogenase prevents abdominal adhesions in a rat model without systemic side effects.

BACKGROUND: Abdominal adhesions are one of the most common complications after abdominal surgery, and fibrin is suspected to be a crucial component. The aim of the current study was an in vivo evaluation of a new recombinant fibrinogenase (AK03) in two animal models. METHODS: Sixty-four rats were randomly divided into four groups (sodium chloride [NaCl], icodextrin, AK03 low dose, and AK03 high dose) and evaluated at two time endpoints. Adhesion model comprised both a visceral defect (terminal ileum) and parietal defect. Test (AK03) and control substances (NaCl and icodextrin) were administered intraperitoneally after setting the intraabdominal defects. A second dose was administered 24 h after surgery. Plasma fibrinogen values were taken at baseline and after 7 and 21 d, respectively. Rats were sacrificed after 7 or 21 d for macroscopic (Diamond score) and immunohistochemical investigations. RESULTS: After 7 and 21 d, the Diamond score of postsurgical adhesions were significantly lower in both AK03-treated groups compared with NaCl control group (P = 0.02). There were no unspecific systemic side effects in both treatment groups and no decrease in plasma fibrinogen concentration. In none of the four groups was there any evidence for impaired wound repair. Microscopically in the area of the parietal defect, we saw less cluster of differentiation 3+ T-lymphocytes and cluster of differentiation 68+ macrophages in both groups receiving AK03 compared with the NaCl and icodextrin control groups. CONCLUSIONS: The results of this study indicate that the new recombinant fibrinogenase AK03 effectively prevents peritoneal adhesions without causing side effects, notably systemic fibrinogen depletion, bleeding, or impaired wound repair. Due to these results, future clinical studies may be promising.

Polyvinylidene Fluoride as a Suture Material: Evaluation of Comet Tail-Like Infiltrate and Foreign Body Granuloma.

BACKGROUND: Biocompatibility and tissue integration of a surgical suture are decisive factors for wound healing and therefore for the success of sutures. The optimal suture material is still under discussion. Polyvinylidene fluoride (PVDF) is described to have superior properties of biocompatibility and is therefore frequently used as a mesh component. Only little information is available about its use as a suture material. The aim of this study was to evaluate the biocompatibility of PVDF as a suture material in comparison to 5 different established sutures in a rat model. METHODS: In 30 male rats, a monofilamental PVDF suture (Resopren®) and 5 established control suture materials [polyester (Miralene®), polytetrafluoroethylene (Gore®), poliglecaprone (Monocryl®), polydioxanone (Monoplus®), polyglactin 910 (Vicryl®), USP size 3-0] were placed in the subcutaneous layer of the abdominal wall without knot or tension. After 3, 7 or 21 days, the abdominal walls were explanted for histopathological and immunohistochemical investigation with special regard to the size and quality of foreign body granuloma and the length of the comet tail-like infiltrate (CTI). RESULTS: The PVDF sutures showed the smallest size of foreign body granuloma (60 ± 14 µm) and the smallest CTI length (343 ± 60 µm) of all polymers after 21 days. Only PVDF (Resopren) and polydioxanone (Monoplus) showed a significant collagen I/III ratio increase between days 3 and 21 (p = 0.009 and p = 0.016). The quality of foreign body reaction regarding inflammation, proliferation and fibrotic remodeling was similar between all suture materials. CONCLUSIONS: Our data indicate that monofilamental PVDF sutures show a favorable foreign body reaction with small granuloma sizes and CTI length in comparison to established sutures. Its use as a suture material in general surgery could therefore be extended in the future. To reinforce these findings, further clinical studies need to be conducted.

Influence of intraoperative radiotherapy (IORT) on perioperative outcome after surgical resection of rectal cancer.

BACKGROUND: Intraoperative radiotherapy (IORT) for locally advanced or recurrent rectal cancer as an integral part of multimodal treatment might be an option to reduce local cancer recurrence. The aim of the present study was to determine the influence of IORT on the postoperative outcome and complications rates in the treatment of patients with adenocarcinoma of the rectum in comparison to patients with rectum resection only. METHODS: A total of 162 patients underwent operation for International Union against Cancer stage III/IV rectal cancer or recurrent rectal cancer at our surgical department between 2004 and 2012. They were divided into two groups depending on whether they received IORT or not. General patient details, tumor, and operation details, as well as perioperative major and minor complications, were registered and compared. RESULTS: Of the 162 patients treated for stage III/IV rectal cancer, 52 underwent rectal resection followed by IORT. Complication rates were similar in the two groups. Operative time was significantly longer in the IORT group (248 ± 84 vs 177 ± 68 min; p < 0.001). No significant differences were found concerning anastomotic leakage rate, hospital stay, or wound infection rate. CONCLUSIONS: Intraoperative radiotherapy appears to be a safe treatment option in patients with locally advanced or recurrent rectal cancer with acceptable complication rates. The effect on local recurrence rate has to be estimated in long-term follow-up.

Two Polyurethane Adhesives for PVDF Fixation Show Superior Biocompatibility in a Rat Model.

BACKGROUND: The current standard for open and laparoscopic repair of incisional hernia consist of an abdominal wall augmentation by mesh implantation. However, the ideal fixation method of the prothesis material remains under discussion, due to potential complications of conventional fixation methods such as chronic abdominal pain or intestinal obstruction. As the use of adhesive based mesh fixation is an option of growing interest, the aim of this experimental study was to investigate the strength and biocompatibility of two newly developed polyurethane-based adhesives in comparison to a cyanoacrylatic adhesive, which is currently in clinical use. METHODS: Two experimental polyurethane/urea-based adhesives (Adhesive-A and Adhesive-B) were compared to a conventional cyanoacrylatic adhesive and an untreated control group. Biomechanical testing was carried out using a pull-out test in uniaxial tensile mode, while biocompatibility assessment was performed in a rat model with 40 Sprague-Dawley rats receiving a subcutaneous implanted PVDF mesh fixed by the corresponding adhesive. Histological and immunohistochemical analysis by a Tissue FAXS system examined the tissue integration of the mesh/adhesive combination and characterized the foreign body reaction. RESULTS: Biomechanical testing of the mesh/adhesive combinations showed a minimal strength of 15.08 N without a significant difference between the groups. Cellular penetration into the mesh/adhesive interface was significantly improved after application of polyurethane adhesives and Adhesive-A showed a significantly lower migration of CD68 positive cells to the adhesive sites compared to cyanoacrylate after 7 days. CONCLUSION: The developed polyurethane-based adhesives are a promising alternative with sufficient adhesive strength and superior short-term biocompatibility to cyanoacrylate.

Ultra-Fine Polyethylene Hernia Meshes Improve Biocompatibility and Reduce Intraperitoneal Adhesions in IPOM Position in Animal Models.

(1) Introduction: The intraperitoneal onlay mesh technique (IPOM) is widely used to repair incisional hernias. This method has advantages but suffers from complications due to intraperitoneal adhesion formation between the mesh and intestine. An ideal mesh minimizes adhesions and shows good biocompatibility. To address this, newly developed multifilamentous polyethylene (PET) meshes were constructed from sub-macrophage-sized monofilaments and studied regarding biocompatibility and adhesion formation. (2) Methods: We investigated fine (FPET, 72 filaments, 11 µm diameter each) and ultra-fine multifilament (UFPET, 700 filaments, 3 µm diameter each) polyethylene meshes for biocompatibility in subcutaneous implantation in rats. Adhesion formation was analyzed in the IPOM position in rabbits. Geometrically identical mono-filamentous polypropylene (PP) Bard Soft® PP meshes were used for comparison. Histologic and immune-histologic foreign body reactions were assessed in 48 rats after 7 or 21 days (four mesh types, with two different mesh types per rat; n = 6 per mesh type). Additionally, two different mesh types each were placed in the IPOM position in 24 rabbits to compile the Diamond peritoneal adhesion score after the same timeframes. The biocompatibility and adhesion score differences were analyzed with the Kruskal-Wallis nonparametric statistical test. (3) Results: Overall, FPET and, especially, UFPET showed significantly smaller foreign body granulomas compared to PP meshes. Longer observation periods enhanced the differences. Immunohistology showed no significant differences in the cellular immune response and proliferation. UFPET demonstrated significantly reduced peritoneal adhesion formation compared to all other tested meshes after 21 days. (4) Conclusions: Overall, FPET and, especially, UFPET demonstrated their suitability for IPOM hernia meshes in animal models by improving major aspects of the foreign body reaction and reducing adhesion formation.

Chronological evaluation of inflammatory mediators during peritoneal adhesion formation using a rat model.

PURPOSE: The inflammatory response to peritoneal injury is considered to be of particular importance in adhesion formation. The aim of this study was to investigate the dynamics of inflammatory mediators in peritoneal adhesions. METHODS: In 60 male rats, a peritoneal defect was performed using a standardized cecal abrasion model. On days 3, 5, 14, 30, 60, and 90, ten animals were sacrificed. The expression of five integral mediators for the cellular immune response (macrophages, T lymphocytes), inflammation (COX-2), cell differentiation, and proliferation (ß-catenin, c-myc) in visceral and parietal adhesions were analyzed. RESULTS: A distinct infiltration of macrophages was observed in all animals up to the 90th postoperative day with a peak on day 3 for visceral adhesions (26.3 ± 5.6%) and on day 14 for parietal adhesions (5.1 ± 1.1%). Compared to parietal adhesions, macrophage levels were significantly higher on day 3 (p = 0.001) and 5 (p = 0.002) but significantly lower on days 30, 60, and 90 in visceral adhesions (p = 0.041; p = 0.001; p = 0.017). T lymphocytes were detected over time with the highest levels on day 3 (visceral 4.0 ± 0.7%; parietal 6.7 ± 2.9%). High levels of COX-2 expression could be detected for the whole observation period. Positive expression of both ß-catenin and c-myc was detected in persistent adhesions; however, no expression of c-myc was observed in parietal adhesions. CONCLUSIONS: The inflammatory reaction in adhesions is not limited to the early postoperative phase. Macrophages may be fundamental in triggering adhesions, and the presence of T cells indicates an additional role of the adoptive immune system. Identification of chemokines and chemokine receptors that trigger the cellular immune response might be a potential option to minimize adhesion formation.

Cross-section modified and highly elastic sutures reduce tissue incision and show comparable biocompatibility: in-vitro and in-vivo evaluation of novel thermoplastic urethane surgical threads.

Surgical sutures are indispensable for a vast majority of operative procedures. An ideal suture is characterized by high tissue compliance without cutting into the mended tissue and optimal biocompatibility. Therefore, we assessed these mechanical and biological properties for novel elastic thermoplastic polyurethane (TPU) and cross-sectional modified "snowflake" sutures. Circular and "snowflake"-shaped TPU threads were manufactured and compared to similar surface modified polyvinylidene fluoride (PVDF) sutures. Regular PVDF sutures were used as the control group. Single-axis tensile test with and without gelatinous tissue surrogates were performed to evaluate the suture incision into the specimens. Biocompatibility was evaluated by subcutaneous implantation (n = 18) in rats for 7 and 21 days. Histology and immunohistology was conducted for assessment of the foreign body reaction. Regular and modified TPU threads showed a significant reduction of incision into the tissue surrogates compared to the control. Both TPU sutures and the modified PVDF sutures achieved comparable biocompatibility versus regular PVDF threads. Detailed histology revealed novel tissue integration into the notches of the surface modified sutures, we termed this newly shaped granuloma "intrafilamentous" granuloma. Elastic TPU threads showed a significant reduction of tissue surrogate incision and suture tension loss. Biocompatibility did not significantly differ from standard PVDF. Histology demonstrated tissue ingrowth following the surface modification of the suture referred to as "intrafilamentous" granuloma. Further in vivo studies are required to illuminate the exact potential of the new sutures to optimize intestinal anastomosis.

A peritoneal defect covered by intraperitoneal mesh prosthesis effects an increased and distinctive foreign body reaction in a minipig model.

BACKGROUND: The incidence of incisional hernia is with up to 30% one of the frequent long-term complication after laparotomy. After establishing minimal invasive operations, the laparoscopic intraperitoneal onlay mesh technique (lap. IPOM) was first described in 1993. Little is known about the foreign body reaction of IPOM-meshes, which covered a defect of the parietal peritoneum. This is becoming more important, since IPOM procedure with peritoneal-sac resection and hernia port closing (IPOM plus) is more frequently used. METHODS: In 18 female minipigs, two out of three Polyvinylidene-fluoride (PVDF) -meshes (I: standard IPOM; II: IPOM with modified structure [bigger pores]; III: IPOM with the same structure as IPOM II + degradable hydrogel-coating) were placed in a laparoscopic IPOM procedure. Before mesh placement, a 2x2cm peritoneal defect was created. After 30 days, animals were euthanized, adhesions were evaluated by re-laparoscopy and mesh samples were explanted for histological and immunohistochemichal investigations. RESULTS: All animals recovered after implantation and had no complications during the follow-up period. Analysing foreign body reaction, the IPOM II mesh had a significant smaller inner granuloma, compared to the other meshes (IPOM II: 8.4 µm ± 1.3 vs. IPOM I 9.1 µm ± 1.3, p < 0.001). The degradable hydrogel coating does not prevent adhesions measured by Diamond score (p = 0.46). A peritoneal defect covered by a standard or modified IPOM mesh was a significant factor for increasing foreign body granuloma, the amount of CD3+ lymphocytes, CD68+ macrophages and decrease of pore size. CONCLUSION: A peritoneal defect covered by IPOM prostheses leads to an increased foreign body reaction compared to intact peritoneum. Whenever feasible, a peritoneal defect should be closed accurately before placing an IPOM-mesh to avoid an excessive foreign body reaction and therefore inferior biomaterial properties of the prosthesis.

Impact of obesity on postoperative complications after laparoscopic and open incisional hernia repair - A prospective cohort study.

BACKGROUND: Obese patients are often required to lose weight prior to incisional hernia repair as obesity is thought to increase postoperative complications and recurrence rates. The aim of this study was to determine the impact of BMI on the outcome after laparoscopic and open incisional hernia repair. MATERIALS AND METHODS: In a cohort study from May 2012 to August 2016, 178 patients underwent incisional hernia repair: 90 patients open SUBLAY and 88 patients laparoscopic intraperitoneal onlay mesh (IPOM). Patients' characteristics, hernia size and postoperative complications were prospectively recorded. Patients were divided into two groups according to their weight: non-obese (BMI < 30 kg/m2) and obese (BMI ≥ 30 kg/m2). In October 2016, eligible patients were assessed for recurrence. RESULTS: 109 patients (61%) were non-obese; 69 patients (39%) were obese. Morbidity rate was higher among obese patients without reaching statistical significance (35% versus 22%; p = 0.083). BMI had no impact on length of hospital stay. The mean duration of surgery was significantly longer for patients with a BMI ≥30 kg/m2 (82 min versus 98 min; p = 0.026). Duration of surgery in particular was significantly longer for obese patients that underwent open SUBLAY repair (p = 0.001). 119 patients (67%) were available for follow-up. Recurrence rates also showed no significant difference between both groups (7% versus 8%, p = 0.856). CONCLUSION: Morbidity rate following incisional hernia repair is not significantly higher in obese than in non-obese patients. BMI has no significant impact on the recurrence rate. Laparoscopic IPOM could be beneficial for obese patients with regard to duration of surgery.

Biomechanical analyses of prosthetic mesh repair in a hiatal hernia model.

Recurrence rate of hiatal hernia can be reduced with prosthetic mesh repair; however, type and shape of the mesh are still a matter of controversy. The purpose of this study was to investigate the biomechanical properties of four conventional meshes: pure polypropylene mesh (PP-P), polypropylene/poliglecaprone mesh (PP-U), polyvinylidenefluoride/polypropylene mesh (PVDF-I), and pure polyvinylidenefluoride mesh (PVDF-S). Meshes were tested either in warp direction (parallel to production direction) or perpendicular to the warp direction. A Zwick testing machine was used to measure elasticity and effective porosity of the textile probes. Stretching of the meshes in warp direction required forces that were up to 85-fold higher than the same elongation in perpendicular direction. Stretch stress led to loss of effective porosity in most meshes, except for PVDF-S. Biomechanical impact of the mesh was additionally evaluated in a hiatal hernia model. The different meshes were used either as rectangular patches or as circular meshes. Circular meshes led to a significant reinforcement of the hiatus, largely unaffected by the orientation of the warp fibers. In contrast, rectangular meshes provided a significant reinforcement only when warp fibers ran perpendicular to the crura. Anisotropic elasticity of prosthetic meshes should therefore be considered in hiatal closure with rectangular patches.

Surgical technique for gastroesophageal reflux disease.

AIMS: Laparoscopic fundoplication is the standard surgical therapy for managing gastroesophageal reflux disease. According to the pre-existing esophageal motility of the patient, tailoring antireflux surgery has been proposed in order to avoid postoperative dysphagia. Thus, the aim of this study is to evaluate the long-term results following this tailored concept. METHODS: One-hundred sixty patients were included in this prospective study. A 360° Nissen fundoplication (NF) was performed on n = 127 patients with a normal esophageal peristalsis, whereas a 270° Toupet fundoplication (TF) was conducted on n = 33 patients having an esophageal motility disorder. Before surgery, all the patients were subjected to pH-metry, manometry, gastroscopy, and they had to respond to a standardized questionnaire. Postoperatively, pH-metry, and manometry were performed. In addition to the questionnaire, side effects and complications were evaluated. RESULTS: The NF cohort and the TF cohort were each followed up for an average of 39 ± 13 months and 43 ± 12 months, respectively. Dysphagia was significantly reduced after NF (p = .033). The TF, however, decreased the intensity but not the incidence of dysphagia (p = .884). Heartburn was significantly diminished in both cohorts. The DeMeester score was significantly reduced after NF, whereas it was not significantly reduced following TF with a still evident, pathological acid reflux occurring postoperatively. CONCLUSION: Our data indicate that tailoring antireflux surgery to the esophageal motility of the patient seems unnecessary. In summary, technical surgical aspects appear to be more important for clinical outcome.

Operative outcome of colon interposition in the treatment of esophageal cancer: a 20-year experience.

BACKGROUND: In patients with esophageal cancer and a history of gastric surgery, colonic interposition is the treatment of choice. Our aim was to review our experience with this technique and to identify possible predictors of the clinical outcome. METHODS: Between 1986 and 2006, 43 patients underwent esophageal reconstruction accomplished by colon interposition in our surgical department. Data from these patients were collected consecutively and reviewed retrospectively. RESULTS: Colon interposition was performed isoperistaltically in 15 patients and was performed in 28 patients anisoperistaltically. In 18 patients, the right colon was used for interposition, whereas in 25 patients, the left colon was used. The mean survival time was 23+/-29 months. Artificial ventilation more than 24h, tumor differentiation grade III, the presence of major complications, and the presence of multivisceral resection had a significant negative influence on the operative outcome of colon interposition for esophageal replacement. CONCLUSION: Colon interposition for esophageal replacement provides a satisfactory operative outcome with high complication rates. Therefore, it should be reserved as a treatment of second choice for cases in which the stomach is not available.