What is the evidence for the use of biologic or biosynthetic meshes in abdominal wall reconstruction?

INTRODUCTION: Although many surgeons have adopted the use of biologic and biosynthetic meshes in complex abdominal wall hernia repair, others have questioned the use of these products. Criticism is addressed in several review articles on the poor standard of studies reporting on the use of biologic meshes for different abdominal wall repairs. The aim of this consensus review is to conduct an evidence-based analysis of the efficacy of biologic and biosynthetic meshes in predefined clinical situations. METHODS: A European working group, "BioMesh Study Group", composed of invited surgeons with a special interest in surgical meshes, formulated key questions, and forwarded them for processing in subgroups. In January 2016, a workshop was held in Berlin where the findings were presented, discussed, and voted on for consensus. Findings were set out in writing by the subgroups followed by consensus being reached. For the review, 114 studies and background analyses were used. RESULTS: The cumulative data regarding biologic mesh under contaminated conditions do not support the claim that it is better than synthetic mesh. Biologic mesh use should be avoided when bridging is needed. In inguinal hernia repair biologic and biosynthetic meshes do not have a clear advantage over the synthetic meshes. For prevention of incisional or parastomal hernias, there is no evidence to support the use of biologic/biosynthetic meshes. In complex abdominal wall hernia repairs (incarcerated hernia, parastomal hernia, infected mesh, open abdomen, enterocutaneous fistula, and component separation technique), biologic and biosynthetic meshes do not provide a superior alternative to synthetic meshes. CONCLUSION: The routine use of biologic and biosynthetic meshes cannot be recommended.

[Comparison of Open vs. Laparoscopic Techniques in Complete Mesocolic Excision (CME) During Right Hemicolectomy]. / Vergleich der offenen vs. laparoskopischen Technik der kompletten mesokolischen Exzision (CME) bei der Hemikolektomie rechts.

AIMS: The technique of open complete mesocolic excision (CME) has improved the outcomes of patients with colon carcinoma. Meanwhile it has become an established international standard procedure. It remains unclear if laparoscopic procedures are able to match the high quality of open resections. A video comparison of the two methods gives insight into the different dissection techniques. INDICATION: Open CME is demonstrated in a 79-year-old female patient with an asymptomatic carcinoma of the ascending colon verified by histopathology. The tumour was diagnosed during routine colonoscopy. No distant metastases were identified during the staging procedure. Laparoscopic CME is performed in a 72-year-old female patient with a biopsy-proven carcinoma of the ascending colon. Similarly this patient was diagnosed during a screening colonoscopy and had no distant metastasis. METHODS: During open CME the ascending colon and the duodenum are mobilised by sharp dissection between the parietal and visceral layer of the mesentery. Afterwards the ascending and transverse mesocolon are dissected from the duodenum and pancreas. The parietal and the visceral mesentery are strictly preserved during these procedures. After the exposure of the superior mesenteric artery and vein, a central dissection of the vessels follows. The colon is cut 10 cm distal to the carcinoma. An ileotransversostomy is performed with a running suture. The hole in the mesentery is closed. The laparoscopic CME is performed using the 4-trocar technique with an umbilical camera position following a medial to lateral approach with primary dissection of the superior mesenteric vein. Radicular vessel ligation opens the space dorsal to the mesocolon with the border lamella remaining intact. The space is widened until the ascending colon is entirely mobilised. The mobilised colon is eventrated through an enlarged umbilical midline incision. Colon resection and the subsequent two-layered side-to-side ileotransversostomy are performed in a standard open surgical fashion. CONCLUSION: Open and laparoscopic CME enable central vessel dissection while preserving the mesenteric layers. However, the laparoscopic procedure is technically demanding and should therefore only be performed by surgeons experienced in laparoscopy.

[Use of biological meshes in abdominal wall reconstruction. Results of a survey in Germany]. / Einsatz biologischer Netze bei der Bauchdeckenrekonstruktion. Ergebnisse einer Umfrage in Deutschland.

BACKGROUND: Surgical treatment of incisional hernia includes implantation of a mesh. The use of synthetic grafts in contaminated fields results in an increased risk of infection. In these cases a potential advantage is described for biological repair material. Evidence for this problem is lacking; therefore, we initiated a survey among surgeons in Germany concerning this question. MATERIAL AND METHOD: A survey concerning indications, experience and techniques of using synthetic and biological meshes was sent to 60 surgical departments. The emphasis of the survey was on the differentiation of clean and contaminated fields. RESULTS: The survey was answered by 42 %. The use of biological repair material was preferred in clean-contaminated, contaminated and soiled fields. Synthetic meshes were preferred in clean, rarely in clean-contaminated and not in contaminated or soiled situations. Primary suture repair was chosen in clean fields and barely in contaminated fields. For closure of giant hernias a component separation technique (CST) was favored by the majority of respondents. A single stage repair was preferred by most of the surgeons even in cases with simultaneous stoma takedown. A total of 72 % of the respondents were satisfied with the use of biological repair material, but the reimbursement was considered to be inappropriate. DISCUSSION: Although the response rate was low, this survey gives an idea of the attitude towards the use of synthetic and biological meshes. Biological repair material is favored for hernia repair in contaminated or soiled fields. The advantage of this choice is a one stage repair despite the contamination. As the results of this survey are not able to provide arguments for the use of different meshes this question should be further investigated with a randomized controlled trial.

[Inguinal hernia: laparoscopic or open surgery?]. / Leistenhernienversorgung: Laparoskopisch oder konventionell?

BACKGROUND: Today, mesh repair is the preferred technique in surgery of inguinal hernia. Whether the mesh should be placed laparoscopically or by open techniques is still controversial. METHODS: A comparison of open mesh and laparoscopic techniques was made with the help of meta-analyses and prospective trials. Outcome variables analysed were recurrence, chronic pain, recovery, morbidity and costs. RESULTS: With regard to recurrence rates, both techniques gave comparable results. The laparoscopic technique shows advantages in terms of morbidity, recovery and especially a lower rate of chronic pain. Open mesh repair has the advantage of a lower risk of some rare severe intra-abdominal complications and seems to be more cost-effective. CONCLUSION: Both techniques of inguinal hernia repair are effective and safe. Each technique has its advantages and disadvantages. Therefore, today no single technique can be recommended as a gold standard.

[Hepatic angiomyolipoma--a rare liver tumor]. / Das Angiomyolipom der Leber--eine seltene Differenzialdiagnose der Leberraumforderung.

A 22-year-old woman was treated for a hepatic lesion with a high suspicion of a liver adenoma at another hospital. The patient presented with unspecific abdominal pain. Further physical examination was unremarkable. A biopsy of the liver lesion revealed hepatic adenoma. Because of the increasing tumour size over a one-year period the patient was referred to our department for surgical therapy. On MRI scan, the liver mass measured 10 x 9 x 9 cm in the right liver lobe with contact to the right hilum. Because of the histological signs of adenoma a right hepatic lobectomy was performed. Postoperative follow-up was uneventful. The pathological diagnosis of hepatic angiomyolipoma was obtained. Angiomyolipoma of the liver is a rare benign mesenchymal tumour often mimicking other hepatic lesions. Histological features are thick-walled blood vessels, mature fat and smooth muscle in various proportions. The biological behaviour of the tumour is benign, although distant metastases are occasionally possible. Due to the potential for malignant transformation, tumour resection should be performed.

[Local and systemic hemostasis in surgery]. / Möglichkeiten der lokalen und systemischen Blutstillung bei chirurgischen Eingriffen.

Surgery inevitably leads to bleeding, and hemostasis aims at reducing the amount of blood loss and the need for transfusion as well as preventing rebleeding, hematoma formation, and the need for repeat surgery. Various locally applicable agents are in use including bone wax, gelatin, collagen, oxidized regenerated cellulose, fibrin sealant glues, and synthetic glues. Some evidence from randomized controlled trials (RCT) exists regarding the use of fibrin sealants on their own or combined with collagen fleece. Systemic hemostasis may be achieved with lysine analogs such as epsilon-aminocaproic acid or tranexamic acid and aprotinin, which are inhibitors of fibrinolysis. There is much albeit sometimes conflicting evidence from RCT regarding the use of these substances in surgery. The role of recombinant activated factor VII in achieving systemic hemostasis is being investigated.

Short-term statin treatment improves endothelial function and neurohormonal imbalance in normocholesterolaemic patients with non-ischaemic heart failure.

OBJECTIVES: To investigate the effect of short-term statin treatment on impaired endothelium-dependent vasodilatation and haemodynamic abnormalities typically occurring in chronic heart failure (CHF). METHODS: In a double-blind, crossover study endothelium-dependent vasodilatation was measured in conduit and resistance vessels of 23 patients with non-ischaemic CHF after 6 weeks of placebo and 40 mg atorvastatin. The haemodynamic impact was assessed by cardioendocrine hormones, echocardiography and clinical indicators of CHF. RESULTS: Cholesterol concentrations were population average (low density lipoprotein 3.56 (SEM 0.16) mmol/l, triglycerides 1.70 (0.20) mmol/l and high density lipoprotein 1.17 (0.07) mmol/l). In resistance vessels, the area under the curve ratio during acetylcholine infusion increased from 9.2 (1.9) with placebo to 12.2 (2.1) with statin (p < 0.01). This improvement was reversed during co-infusion with the nitric oxide antagonist N(G)-monomethyl-L-arginine. In conduit arteries, flow-mediated dilatation increased from 5.64 (SEM 0.88)% with placebo to 6.83 (0.97)% with statin (p < 0.05). Endothelium-independent vasodilatation did not change (p = 0.68 for conduit and p = 0.45 for resistance vessels). Endothelin 1 and atrial natriuretic peptide (ANP) decreased from 1.57 (0.08) and 51.3 (1.0) with placebo to 1.42 (0.09) pg/ml (p < 0.05) and 42.1 (7.5) pmol/l (p < 0.05), respectively, with statin. CONCLUSIONS: In patients with non-ischaemic CHF and population-average cholesterol concentrations, short-term statin treatment improves endothelial function in conduit and resistance vessels and lowers plasma endothelin 1 and ANP concentrations.

The postprandial state does not impair endothelial function in women with type 2 diabetes irrespective of glycaemic control.

AIMS/HYPOTHESIS: The postprandial state has been shown to be associated with endothelial dysfunction, a predictor of cardiovascular morbidity. In type 2 diabetes, postprandial metabolic excursions are prolonged and exaggerated, but less pronounced if glycaemic control is optimised. We investigated the impact of improved glycaemic control on endothelial function in the postprandial state. METHODS: We studied 19 postmenopausal women with type 2 diabetes and ten non-diabetic subjects. Participants with diabetes were re-studied 3 months after intensive glucose regulation. We measured forearm blood flow by strain gauge plethysmography during rest, during acetylcholine infusion and post ischaemia in the fasting state, and again 3 hours after a mixed meal (660 kcal, 55% fat). RESULTS: Endothelium-dependent vasodilation was impaired in the diabetic group (p<0.005) and improved following an HbA1c reduction of 0.96% (p<0.05 for high-dose acetylcholine infusion). Postprandial metabolic excursions were higher in the diabetic group (p<0.001, p<0.01 and p<0.05 for glucose, insulin and triglycerides respectively). Resting forearm blood flow increased in all groups after the meal (p<0.005). There was no difference in fasting and postprandial endothelium-dependent vasodilation before and after improved glucose regulation in either group. CONCLUSIONS/INTERPRETATION: The postprandial state does not impair endothelial function in non-diabetic women and does not make pre-existing endothelial dysfunction worse in women with type 2 diabetes, irrespective of glycaemic control.

From atoms to systems: a cross-disciplinary approach to complement-mediated functions.

With an ever-increasing wealth of information made available to researchers from expanding genomic sequence and protein structure databases, traditional experimentation and research are being drastically revisited. The unidirectional study of single molecules and pathways is being replaced by a combinatorial and cross-disciplinary platform that investigates interactive biological systems and dynamic networks. The complement system constitutes an ideal paradigm of how this concept is being applied in the field of contemporary immunology. Our laboratory has adopted such a cross-disciplinary approach in elucidating key aspects of complement functions and determining the role of several complement proteins in both inflammatory and developmental processes. Here we discuss recent findings pertaining to the rational development of complement inhibitors, our studies on protein-protein interactions and our progress in the study of viral immune evasion and complement evolution. Furthermore, we present recent studies implicating complement components in complex developmental processes, such as organ regeneration, hematopoietic development, and stem cell engraftment.

[Preoperative examination of potential kidney transplantation donors: value of gadolinium-enhanced 3D MR angiography in comparison with DSA and urography]. / Präoperative Untersuchung potentieller Nierenlebendspender: Wertigkeit der Gadoliniumverstärkten 3D-MR-Angiographie im Vergleich mit der DSA und Urographie.

PURPOSE: To assess a contrast-enhanced standardized MRA protocol for the presurgical evaluation of potential renal transplant donors. METHODS: Twenty-three potential donors for renal transplantations were examined with gadolinium-enhanced, two-phase MR angiograms (1.5 T) and DSA/urography for the number of renal arteries, the presence of aberrant arterial and venous branches, renal artery stenoses and anatomy of the renal collecting system and ureters. The diagnostic value was assessed by evaluating different image processing modalities and interobserver variability. RESULTS: Using maximum intensity projections (MIP) together with multiplanar reformatting (MPR), accessory arteries were detected with a sensitivity/specificity of 100%/98%. Depending on diagnostic experience, exclusive evaluation of MIP yielded a sensitivity/specificity of 67-100%/95-100%. Using MIP/MPR, venous depiction was good in 80%, with MIP solely in 30-40%. At least the proximal third of the ureter was visible in 67%. CONCLUSION: MPR/MIP evaluation of two-phase, contrast-enhanced MRA provides an excellent depiction of renal vessel anatomy for presurgical evaluation of renal transplant donors. Exclusive MIP assessment is less reliable and depends strongly on the examiner's experience. For sufficient visualization of the ureters, either additional measurements or low-dose diuretic injection have to performed.