Maternal cytokine status may prime the metabolic profile and increase risk of obesity in children.

BACKGROUND: The maternal inflammation status during pregnancy has been associated with metabolic imprinting and obesity development in the child. However, the influence of the maternal Th2 cytokines, interleukin-4 (IL4), IL5 and IL13, has not been studied so far. METHODS: We investigated the relationship between maternal innate (IL6, IL8, IL10 and tumor necrosis factor-α (TNFa)) and adaptive (interferon-γ, IL4, IL5 and IL13) blood cytokine levels at 34 weeks of gestation and children's overweight development until the age of 3 years in 407 children of the German longitudinal LINA (Lifestyle and Environmental Factors and their Influence on Newborns Allergy risk) cohort. Children's body weight and height were measured during the annual clinical visits or acquired from questionnaires. Body mass index (BMI) Z-scores were calculated according to the WHO reference data to adjust for child's age and gender. Cytokine secretion was stimulated with phytohemagglutinin or lipopolysaccharide and measured by cytometric bead assay. Furthermore, we assessed metabolic parameter in blood of 318 children at age 1 using the AbsoluteIDQ p180 Kit (Biocrates LIFE Science AG). RESULTS: Applying logistic regression models, we found that an increase of maternal IL4 and IL13 was associated with a decreased risk for overweight development in 1- and 2-year-old children. This effect was consistent up to the age of 3 years for IL13 and mainly concerns children without maternal history of atopy. Children's acylcarnitine concentrations at 1 year were positively correlated with maternal IL13 levels and inversely associated with the BMI Z-score at age 1. CONCLUSIONS: We were able to show for the first time that the maternal Th2 status may be linked inversely to early childhood overweight development accompanied by an altered metabolic profile of the fetus. However, our data do not support a direct mediating role of acylcarnitines on maternal IL13-induced weight development.

[Video-assisted retroperitoneal debridement : Minimally invasive treatment and long-term results for necrotizing pancreatitis]. / Videoassistiertes retroperitoneales Débridement : Minimalinvasive Therapie und Langzeitverlauf bei nekrotisierender Pankreatitis.

BACKGROUND: Among patients with necrotizing pancreatitis 15-20% develop infected necrosis, which entails mortality rates of up to 20%. Particularly driven by the results of the Dutch Pancreatitis Study Group there has been a paradigm change from open necrosectomy to step-up treatment with initial percutaneous and/or endoscopic drainage followed, if necessary, by minimally invasive retroperitoneal debridement. AIM OF THE STUDY: Description of case series in which patients underwent video-assisted retroperitoneal debridement (VARD) including follow-up focused on quality of life. METHODS: Systematic cohort study including all patients who underwent a VARD procedure at the Department of General, Visceral and Transplantation Surgery at Aachen University Hospital from 2011 to 2015. Quality of life was recorded using the EORTC QLQ-C 30 questionnaire and compared to a representative sample of the German general population. RESULTS: The VARD procedure was performed in 9 cases, although in 1 case conversion to an open approach due to an acute bleeding was necessary. There was no 30-day and 60-day mortality following VARD. During the postoperative stay no patient required specific treatment for surgical complications. In particular, no enterocutaneous fistula or organ perforation was observed. Regarding the quality of life score there was no significant difference concerning the global health status, compared to the sample from the general population. DISCUSSION: Our data reinforce that a step-up approach in patients with necrotizing pancreatitis is a feasible and safe treatment procedure. For the first time, we could demonstrate satisfactory results in a long-term follow-up including QOL.

Pancreatogastrostomy Versus Pancreatojejunostomy for RECOnstruction After PANCreatoduodenectomy (RECOPANC, DRKS 00000767): Perioperative and Long-term Results of a Multicenter Randomized Controlled Trial.

OBJECTIVES: To assess pancreatic fistula rate and secondary endpoints after pancreatogastrostomy (PG) versus pancreatojejunostomy (PJ) for reconstruction in pancreatoduodenectomy in the setting of a multicenter randomized controlled trial. BACKGROUND: PJ and PG are established methods for reconstruction in pancreatoduodenectomy. Recent prospective trials suggest superiority of the PG regarding perioperative complications. METHODS: A multicenter prospective randomized controlled trial comparing PG with PJ was conducted involving 14 German high-volume academic centers for pancreatic surgery. The primary endpoint was clinically relevant postoperative pancreatic fistula. Secondary endpoints comprised perioperative outcome and pancreatic function and quality of life measured at 6 and 12 months of follow-up. RESULTS: From May 2011 to December 2012, 440 patients were randomized, and 320 were included in the intention-to-treat analysis. There was no significant difference in the rate of grade B/C fistula after PG versus PJ (20% vs 22%, P = 0.617). The overall incidence of grade B/C fistula was 21%, and the in-hospital mortality was 6%. Multivariate analysis of the primary endpoint disclosed soft pancreatic texture (odds ratio: 2.1, P = 0.016) as the only independent risk factor. Compared with PJ, PG was associated with an increased rate of grade A/B bleeding events, perioperative stroke, less enzyme supplementation at 6 months, and improved results in some quality of life parameters. CONCLUSIONS: The rate of grade B/C fistula after PG versus PJ was not different. There were more postoperative bleeding events with PG. Perioperative morbidity and mortality of pancreatoduodenectomy seem to be underestimated, even in the high-volume center setting.

Fascial closure after open abdomen: initial indication and early revisions are decisive factors--a retrospective cohort study.

BACKGROUND: The surgical treatment method in which the peritoneal cavity is opened anteriorly and deliberately left open, hence often called "open abdomen" has become the standard of care in damage-control procedures as well as in the management of intra-abdominal hypertension and in severe intra-abdominal sepsis. Whereas open abdomen has been closed in two stages traditionally, a modern trend is to close the fascial layers within the initial hospitalization to avoid complications like enterocutaneous fistula and hernia formation. The aim of this study was to determine crucial factors influencing the possibility of fascial closure after open abdomen. METHODS: Between 2003 and 2013, 355 adult patients were treated with open abdomen in our institution. Their data were collected and retrospectively analyzed. They were divided into two groups depending on fascial closure or not (fascial closure, n = 137 (39%) vs. non-fascial closure, n = 218 (61%)). RESULTS: The patients who reached fascial closure had a significantly higher rate of initially performed open abdomen (97 patients (71%) vs. 118 (54%), p = 0.002) and the periods of time until a second and a third look operation were significantly shorter (2.7 ± 2.5 vs. 4.2 ± 6.6 days, p = 0.021 and 5.6 ± 3.7 vs. 8.5 ± 8.6 days, p = 0.006). Furthermore, the presence of peritonitis (64 patients (47%) vs. 83 patients (38%), p = 0.023) and large bowel resection (74 patients (54%) vs. 90 patients (41%), p = 0.022) were significantly higher in this group. Rates of in-hospital mortality (97 patients (44%) vs. 38 patients (28%), p = 0.002) and the presence of pancreatitis (19 patients (9%) vs. 3 patients (2%), p = 0.013) were significantly higher in the non-fascial closure group. CONCLUSIONS: The probability to reach fascial closure after open abdomen seems to increase when open abdomen is performed initially and when early second and third look operations are performed. The presence of pancreatitis seems to be the only negative prognostic marker concerning fascial closure.

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.

Skin as marker for collagen type I/III ratio in abdominal wall fascia.

PURPOSE: An altered collagen metabolism could play an important role in hernia development. This study compared collagen type I/III ratio and organisation between hernia and control patients, and analysed the correlation in collagen type I/III ratio between skin and abdominal wall fascia. METHODS: Collagen organisation was analysed in Haematoxylin-Eosin sections of anterior rectus sheath fascia, and collagen type I/III ratio, by crosspolarisation microscopy, in Sirius-Red sections of skin and anterior rectus sheath fascia, of 19 control, 10 primary inguinal, 10 recurrent inguinal, 13 primary incisional and 8 recurrent incisional hernia patients. RESULTS: Compared to control patients [7.2 (IQR = 6.8-7.7) and 7.2 (IQR = 5.8-7.9)], collagen type I/III ratio was significantly lower in skin and anterior rectus sheath fascia of primary inguinal [5.2 (IQR = 3.8-6.3) and 4.2 (IQR = 3.8-4.7)], recurrent inguinal [3.2 (IQR = 3.1-3.6) and 3.3 (IQR = 3-3.7)], primary incisional [3.5 (IQR = 3-3.9) and 3.4 (IQR = 3.3-3.6)] and recurrent incisional hernia [3.2 (IQR = 3.1-3.9) and 3.2 (IQR = 2.9-3.2)] patients; also incisional and recurrent inguinal hernia had lower ratio than primary inguinal hernia patients. Furthermore, collagen type I/III ratio was significantly correlated (r = 0.81; P < 0.001) between skin and anterior rectus sheath fascia. Finally, collagen organisation was comparable between hernia and control patients. CONCLUSIONS: Furthermore, in both skin and abdominal wall fascia of hernia patients, collagen type I/III ratio was lower compared to control patients, with more pronounced abnormalities in incisional and recurrent inguinal hernia patients. Importantly, collagen type I/III ratio in skin was representative for that in abdominal wall fascia.

Suture-free and mesh reinforced small intestinal anstomoses: a feasibility study in rabbits.

INTRODUCTION: Anastomotic leakage still remains a major complication in general surgery. Beside general risk factors, the ideal method of anastomotic technique has not been found until now. The aim of the present study was to analyze wound healing in suture-free small intestine anastomoses using fibrin glue with and without mesh-reinforcement. METHODS: Laparotomy and four different types of small bowel anastomoses were performed in 32 chinchilla rabbits. Standard hand-sewn anastomoses (CG), suture-free glued anastomoses (FG) with and without mesh reinforcement using two different types of meshes [Vicryl-mesh (VM) and Surgisis (SM)]. Animals were sacrificed after 5 and 21 days. Bursting pressure, collagen type I/III ratio, and matrix-metalloproteinase 2, 9, and 13 were analyzed. RESULTS: None of the animals died due to an anastomotic leakage. All animals in the long term group with Surgisis mesh died due to a mechanical bowel obstruction based on a distinctive stenosis of the anastomosis. The bursting pressures did significantly differed in animals with fibrin glue alone compared to animals with Vicryl-mesh reinforcement (p < 0.05). Histological examination revealed statistically significant differences (p < 0.05) in the values for MMP-2 (VM < SM), MMP-9 (VM < CG), and MMP-13 (CG < SM, VM < FG, and VM < SM). However, collagen type I/III ratios were not significantly different between groups. CONCLUSIONS: Our results suggest that a mesh reinforced glued anastomosis is technically feasible. Furthermore, mesh-reinforcement using VM increased the integrity and simplified the technique of suture-free anastomoses.

In vitro and in vivo characteristics of gentamicin-supplemented polyvinylidenfluoride mesh materials.

To reduce infection rates after mesh implantation antibiotic-coated meshes were designed. The aim of the study was to analyze biocompatibility and in vitro efficiency of a modified gentamicin-supplemented polyvinylidenfluoride mesh. Twenty rats were randomized to two groups (PVDF group and Genta group). Mesh material was implanted subcutaneously. Blood samples were taken to determine the gentamicin serum concentration. Seven and 90 days after mesh implantation, animals were euthanized. The inflammatory tissue response was characterized by analyzing the foreign body granuloma. Cellular immune response was analyzed by immunohistochemical investigations. The collagen type I/III ratio was estimated by crosspolarization microscopy. In vitro agar diffusion test, suspension test, and gentamicin release were characterized. Agar diffusion and suspension test showed efficient antibiotic effects of the mesh in vitro. Serum concentrations of gentamicin showed a peak value 1 h postoperatively with a decline within the next day. The total size of the granuloma was significantly smaller in the Genta group compared to the PVDF group at both points of time. Except of a short period of increased expression of CD68 in the Genta group after 7 days, no further difference was found analyzing cellular immune response. The collagen type I/III ratio was widely constant analyzing the two mesh types without significant differences comparing both mesh materials. A significantly decreased foreign body granuloma formation compared to the pure PVDF mesh group was found. In vitro analysis showed efficient antibiotic effects of the Gentamicin supplementation compared to the pure PVDF mesh.

Comparison of long-term biocompability of PVDF and PP meshes.

BACKGROUND: Abdominal hernia repair is the most frequently performed operation in surgery. Mesh repair in hernia surgery has become an integral component. Although meshes made of PVDF are already in clinical use, so far no data of long-term biocompability are available. METHODS: In this study a PVDF mesh was compared to a polypropylene mesh with regard to its long-term biocompatibility. A total of 28 rats were randomized to two groups. Mesh material was implanted subcutaneously; animals were euthanized seven days and six months postoperatively. The quantity of inflammatory tissue response was characterized by measuring the diameter of the foreign body granuloma. Furthermore quality of cellular immune response (T-lymphocytes, macrophages, and neutrophils), and inflammation (COX-2) was analyzed by immunohistochemistry. Furthermore the collagen type I/III ratio was determined. RESULTS: Macrophages, T-lymphocytes, neutrophiles, and COX-2 declined significantly up to six months postoperatively in comparison to day 7 for both PVDF and PP meshes, and in both groups the collagen ratio increased significantly in the course of time. PVDF meshes showed a foreign body granuloma size significantly reduced compared to PP (7 days: 20 ± 2 µm vs. 27 ± 2 µm; 6 months 15 ± 2 µm vs. 22 ± 3 µm; p < .001). However no significant differences were found analyzing cellular response six months postoperatively. CONCLUSIONS: Our current data suggest that even in the long-term course after six months and despite a higher effective surface of the PVDF samples it showed a smaller foreign body granuloma than with PP whereas the cellular response was similar.

Impact of pressure and gas type on adhesion formation and biomaterial integration in laparoscopy.

BACKGROUND: Laparoscopic mesh repair of inguinal and incisional hernias has been widely adopted. Nevertheless, knowledge about the impact of pneumoperitoneum on mesh integration is rare. The present study investigates pressure and gas-dependent effects of pneumoperitoneum on adhesion formation and biomaterial integration in a standardized animal model. METHODS: Laparoscopic intraperitoneal onlay mesh implantation (IPOM) was performed in 32 female chinchilla rabbits using CO(2) or helium for pneumoperitoneum. Intra-abdominal pressures were 3 or 6 mmHg. Animals were killed after 21 days, and the abdominal wall was explanted for subsequent histopathological examinations. Adhesions were assessed qualitatively with a scoring system, and the adhesion surface was analyzed semiquantitatively by planimetry. Infiltration of macrophages (CD68), expression of matrix metalloproteinase 13 (MMP-13), and cell proliferation (Ki67) were analyzed at the mesh to host interface by immunohistochemistry. The collagen type I/III ratio was analyzed by cross-polarization microscopy to determine the quality of mesh integration. RESULTS: After 21 days, perifilamental infiltration with macrophages (CD68) and percentage of proliferating cells (Ki67) were highest after 6 mmHg of CO(2) pneumoperitoneum. The extent of adhesions, as well as the expression of MMP-13 and the collagen type I/III ratio, were similar between groups. CONCLUSIONS: Our experiments showed no pressure or gas-dependent alterations of adhesion formation and only minor effects on biomaterial integration. Altogether, there is no evidence for a clinically negative effect of CO(2) pneumoperitoneum.

Serum analyses for protein, albumin and IL-1-RA serve as reliable predictors for seroma formation after incisional hernia repair.

PURPOSE: The aim of this study was to identify potential parameters as predictors for seroma formation after incisional hernia mesh repair. METHODS: The incidence of postoperative seroma was determined prospectively in 37 patients who underwent incisional hernia repair with lightweight polypropylene-polyglactin composite mesh (Vypro-II®). Postoperative seroma manifestation was related to patient characteristics (gender, age, BMI, comorbidity, nicotine abuse) and to preoperative serum concentration of total protein, albumin, interleukin-1-receptor-antagonist (IL-1-RA), propeptid-III-procollagen, hyaluronan and fibronectin. Ultrasound investigation was performed on postoperative days 1, 2, 3, 8 and 10. RESULTS: Ten patients (27%) developed seroma with a mean volume of 77 ± 88 ml. Higher BMI correlated with increased seroma formation (P = 0.038). In patients with seroma, total protein (67 ± 7 vs 72 ± 4 g/l; P = 0.037), albumin (42 ± 3 vs 40 ± 4 g/l; P = 0.018) and IL-1-RA (1.4 ± 1 vs 0.8 ± 0.6 U/ml; P = 0.048) exhibited significantly altered serum concentrations in comparison to patients without seroma formation. No significant differences were seen in any other parameters. CONCLUSIONS: High BMI, lowered preoperative serum concentration of total protein and albumin, and high serum concentration of IL-1-RA are related to an elevated risk for postoperative seroma formation.

[Conventional reparation of parastomal hernia]. / Konventionelle Reparation der parastomalen Hernie.

The reparation of parastomal hernias and their recurrence remain problematic although the implementation of mesh techniques has lowered recurrences rates. Conventional surgical techniques include suture repair, relocation of the stoma as well as diverse hernia repair procedures with mesh implantation. Suture repair has been abandoned due to its high recurrence rate. Simple relocation is not recommended because of high rates of recurrent parastomal hernias. Conventional hernia repair using mesh implants is classified according to the mesh position into epifascial (onlay), retromuscular (sublay) and intraperitoneal (IPOM) techniques. Furthermore, a combination of relocation with additional mesh enforcement is also possible. The value of the different mesh techniques and of new biological mesh prostheses must be evaluated in randomized controlled studies.

Different methods of mesh fixation in open retromuscular incisional hernia repair: a comparative study in pigs.

PURPOSE: Reinforcement of the abdominal wall with alloplastic mesh material in incisional hernia repair is well established. To avoid dislocation and migration of the prostheses, mesh fixation is recommended. However, there seems to be a correlation between postoperative pain and mesh fixation. Furthermore, it remains unclear whether mesh fixation is necessary at all. METHODS: A retromuscular mesh implantation was performed in 36 pigs using a polypropylene-polyglecaprone 25 composite mesh (Ultrapro(®), 12 × 18 cm). In group 1, the mesh was fixed to the posterior rectus sheet with non absorbable single sutures (Prolene(®) 2-0), in group 2 fixation was with absorbable sutures (Vicryl(®) 2-0), in group 3 mesh fixation was with 5 ml fibrin sealant (Quixil(®)), and, as a control, there was no fixation in group 4. The abdominal wall was explanted on postoperative day 7, 14 and 56. Mesh size and position was measured, and pull-out force of the mesh was analysed mechanically by tensiometry. The ratio of collagen type I/III was analysed to determine the quality of mesh integration. RESULTS: Neither mesh dislocation nor mesh migration was detected. Mesh size showed no significant differences, whether comparing time points or groups. No significant differences in the tensile strength of mesh integration were found when comparing the groups (group 1: 155 ± 17 mmHg; group 2: 175 ± 9 mmHg; group 3: 166 ± 24 mmHg; group 4: 172 ± 28 mmHg). Though the type I/III collagen ratio increased over time, no significant differences according to the type of fixation used were detected. CONCLUSION: Mesh fixation in open incisional hernia repair with retromuscular mesh augmentation to avoid mesh dislocation or migration in the early postoperative period appears to be unnecessary.

Harrahill's technique: a simple screening test for intra-abdominal pressure measurement.

BACKGROUND: Repair of giant incisional hernias may lead to an increase in intra-abdominal pressure (IAP) and, sometimes, to abdominal compartment syndrome. Measurement of IAP using Kron's technique (Kron et al. in Ann Surg 199:28-30, 1984) is currently accepted as the gold standard, whereas Harrahill has described a simple measurement setup using urinary drainage manometry (Harrahill in J Emerg Nurs 24:465-466, 1998). The aim of this clinical trail was to evaluate the correlation, reproducibility and effectiveness of this device. METHODS: A prospective cohort study was performed in 43 patients undergoing elective standard abdominal intervention with laparotomy. These patients remain under surveillance in the intensive care unit and require a urinary catheter because of the operation. We performed comparative measurements of IAP using both Korn's (IVM) and Harrahill's (UDM) technique. RESULTS: Evaluating the correlation between the IVM and UDM techniques, we measured median IAPs of 9.8 +/- 4.1 mmHg (2.9-19.9 mmHg) and 10.0 +/- 4.1 mmHg (min-max: 1.5-19.9 mmHg), respectively. Pearson's coefficient of correlation was r = 0.97. The average of difference between UDM and IVM was -0.2 +/- 0.9 mmHg with limits of agreement of -1.7 to 2.0 mmHg. Evaluating the reproducibility of Harrahill's technique, we found median IAPs of 10.4 +/- 2.1 mmHg (min-max: 2.9-19.1 mmHg) and 10.4 +/- 2.7 mmHg (3.7-19.9 mmHg), respectively, in 43 comparative measurements (Pearson's coefficient of correlation, r = 0.97. The average difference between both measurements was -0.1 +/- 1.1 mmHg with limits of agreement of -2.3 to 2.2 mmHg. CONCLUSIONS: We were able to demonstrate good correlation and high reproducibility of IAP measurement using Harrahill's technique compared to the gold standard Korn method. We consider this technique as a suitable method for quick and simple screening test for intra-abdominal hypertension, especially after repair of giant incisional hernias.

Evaluation of tissue components in the peripheral nervous system using Sirius red staining and immunohistochemistry: a comparative study (human, pig, rat).

Little is known about species differences in the peripheral nerve system and quantitative evaluation of main tissue components has rarely been done. Nevertheless, animal models are used for example in pain research without exact knowledge of degree of fibrosis in pathological states which would determine possible treatment options. It would therefore be of crucial interest to describe the degree of fibrosis and the remaining functional nerve tissue as exact as possible. In the present study we evaluated collagen (stroma) and nerve fiber (parenchyma) composition of peripheral nerves in three species (human, rat, pig) and used digital colour-separation and analysis for collagen type differentiation and quantification of immuno-positive-stained area. We found similar ratios of collagen types I and III in epineurium and similar immuno-positive area for staining of neurofilament and S-100beta. In contrast, we measured significantly different ratios of collagen type I to type III in the endoneurium. This combined analysis of the main tissue components of peripheral nerves could be an easy-to-use tool in evaluating changes during damage caused by scaring, systemic disease or compression syndromes. The calculated collagen type I/III ratio may serve as an objective diagnostic value for the description or as prognostic marker for therapeutic approaches in peripheral nerve pathology. However, in particular studies of collagen accumulation in nerves, species dependant differences have to be considered.

[Incisional hernia - how do I do it? Standard surgical approach]. / Narbenhernie - Wie ist zu verfahren? Chirurgische Standardversorgung.

Various techniques for repair of an incisional hernia are available for the surgeon. Conventional suture techniques are quick and easy to perform but they are associated with an unacceptable rate of recurrence and therefore should only be used in exceptional cases. An underlying systemic disturbance of collagen metabolism is assumed to exist in patients with an incisional hernia. In such patients the mechanisms of wound healing and remodeling of the abdominal wall following laparotomy are insufficient, which necessitates reinforcement of the abdominal wall with a non-resorbable alloplastic mesh prosthesis to enable a long-term cure. The implantation of such meshes can be carried out laparoscopically or by an open approach. The gold standard of open repair techniques is the retromuscular placement of a mesh prosthesis. The retromuscular mesh placement as a reinforcement of the abdominal wall (augmentation) must be categorically differentiated into the abdominal wall replacement by mesh bridging. In this technique the mesh is likewise placed in the retromuscular space, however a complete closure of the ventral fascia is not necessary. Retromuscular augmentation enables an extra-peritoneal placement of the prosthesis, an optimization of tissue integration by plane coverage of the prosthesis by well vascularized muscular tissue and a sufficient overlap in cranio-caudal and lateral directions. Mesh fixation is best made with absorbable suture material but is better suited for technical simplification. The use of a prophylactic drainage should be decided depending on the individual patient's risk factors, because sufficient evidence-based data are currently not available. If augmentation is not possible bridging is necessary and then the mesh has to be fixed without underlying support. Current data reveal that the recurrence rate following incisional hernia repair by retromuscular mesh augmentation has decreased promisingly in comparison to simple suture techniques. In total the recurrence rate following retromuscular mesh placement ranges between 2 and 12%. Current results of prospective randomized multicentre trials are not available. However, it is to be expected that further development of mesh materials as well as improvement of surgical techniques with avoidance of typical pitfalls will lead to further reduction of the recurrence rate with an improvement in patient satisfaction.

Impact of mesh positioning on foreign body reaction and collagenous ingrowth in a rabbit model of open incisional hernia repair.

BACKGROUND: Incisional hernia remains as one of the most common surgical complications. Different mesh techniques are used in 75-80% of hernia repair. The aim of this study was to evaluate the dependence of mesh positioning and the type of mesh implanted on foreign body reaction and collagenous ingrowth. MATERIALS AND METHODS: In 24 male Chinchilla rabbits, an incisional hernia repair was performed with mesh reinforcement either by sublay (n = 12) or by onlay technique (n = 12). In each group, two different types of mesh prosthesis were investigated: polypropylene (PP, Prolene) and polypropylene-polyglecaprone 25 composite (PP-PG, UltraPro). On postoperative day 60, the inflammatory and connective tissue formation was characterised by measuring the diameter of inner cellular infiltrate and outer fibrous capsule of the foreign body granuloma, and by verifying the collagen type I/III ratio. Furthermore, the expression of matrix metalloproteinase-2 (MMP-2) was analysed. RESULTS: Microscopic investigation of the mesh/host-tissue interface showed typical formation of foreign body granuloma. The diameters of the inner part of the foreign body granuloma representing the amount of inflammatory cell infiltrate were significantly increased in the PP mesh compared to the PP-PG mesh, both in the sublay group (PP 13.1 +/- 1.21 microm vs. PP-PG 11.7 +/- 0.34 microm; P = 0.026) and in the onlay group (PP 13.1 +/- 1.24 microm vs. PP-PG 11.2 +/- 0.55 microm; P = 0.009). The diameter of the fibrous capsule as the outer ring of the granuloma was significantly increased when investigating the PP mesh in sublay position (29.5 +/- 1.12 microm) compared to the PP mesh in onlay position (27.9 +/- 0.73 microm) (P = 0.026). Investigating the quality of perifilamentary collagen deposition expressed as collagen type I/III ratio, the sublay group showed significantly elevated values compared to the onlay group (PP sublay 3.1 +/- 0.18 vs. PP onlay 2.4 +/- 0.41; P = 0.004) (PP-PG sublay 3.5 +/- 0.34 vs. PP-PG onlay 2.6 +/- 0.13; P = 0.002). The analysis of MMP-2 expression revealed no significant differences. CONCLUSION: The beneficial results of mesh reinforcement in the sublay technique might be due to a superior quality of postoperative connective tissue formation. Mesh incorporation, irrespective of positioning, is favourable in low-weight, large, porous mesh material represented by a reduced inflammatory part of the foreign body granuloma.

Haemorrhoids - a collagen disease?

OBJECTIVE: The cause of haemorrhoidal disease is unknown, epidemiological data and histopathological findings support the hypothesis that reduced connective tissue stability is associated with the incidence of haemorrhoids. Therefore the aim of this study was to analyse the quantity and quality of collagen formation in the corpus cavernosum recti in patients with III°/IV° haemorrhoids in comparison with persons without haemorrhoids. METHOD: Haemorrhoidectomy specimens of 31 patients with III°/IV° haemorrhoids were examined. The specimens of 20 persons who died a natural death and who had no haemorrhoidal disease served as the controls. The amount of collagen was estimated photometrically by calculating the collagen/protein ratio. The collagen I/III ratio served as parameter for the quality of collagen formation and was calculated using cross polarization spectroscopy. RESULTS: Patients with haemorrhoids had a significantly reduced collagen/protein ratio (42.2 ± 16.2µg/mg vs 72.5±31.0µg/mg; P= 0.02) and a significantly reduced collagen I/III ratio (2.0±0.1 vs 4.6±0.3; P<0.001) compared with persons without haemorrhoidal disease. There was no correlation with patients' age or gender. CONCLUSIONS: There is a fundamental disorder of collagen metabolism in patients with haemorrhoidal disease. It remains unclear whether this is due to exogenous or endogenous influences.

Hernia repair: the search for ideal meshes.

BACKGROUND: Effective repair of hernia is a difficult task. There have been many advances in hernia repair techniques over the past 50 years, but new strategies must be considered to enhance the success of herniorrhaphy. DISCUSSION: At the 30th International Congress of the European Hernia Society, nine experts in hernia repair and experimental mesh evaluation participated in a roundtable discussion about today's unmet needs in hernia repair, including what constitutes an "ideal" hernia repair and the portfolio of "ideal" mesh prostheses. Defining characteristics of lightweight mesh, mesh alternatives, the surgeon's role in hernia repair, adverse events, the unmet requirements for today's hernia repair, and optimized animal models were among the topics discussed. CONCLUSION: The ideal mesh's construction is still in progress, but greater understanding of its critical characteristics was explored. It is hoped that these suggestions will lead to the development of improved hernia treatments and a maximally effective portfolio of hernia mesh prostheses.