[Show abstract][Hide abstract] ABSTRACT: Lymphatic vessels (LVs) are involved in a number of physiological and pathophysiological processes such as fluid homoeostasis, immune surveillance, and resolution of inflammation and wound healing. Lymphangiogenesis, the outgrowth of existing LVs and the formation of new ones, has received increasing attention over the past decade on account of its prominence in organ physiology and pathology, which has been enabled by the development of specific tools to study lymph vessel functions. Several studies have been devoted to renal lymphatic vasculature and lymphangiogenesis in kidney diseases, such as chronic renal transplant dysfunction, primary renal fibrotic disorders, proteinuria, diabetic nephropathy and renal inflammation. This review describes the most recent findings on lymphangiogenesis, with a specific focus on renal lymphangiogenesis and its impact on renal diseases. We suggest renal lymphatics as a possible target for therapeutic interventions in renal medicine to dampen tubulointerstitial tissue remodelling and improve renal functioning.
Expert Reviews in Molecular Medicine 09/2014; 16(1):e15. DOI:10.1017/erm.2014.18 · 5.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose:
Adhesiolysis at repeat surgery induces adhesion reformation which seems more virulent than development of de novo adhesions. We studied the effect of a new ultrapure alginate gel on adhesion reformation.
In 46 male Wistar rats, adhesion formation was induced using the cecal abrasion and peritoneal sidewall excision procedure. Two weeks later, a second laparotomy was performed, adhesions were graded, and surgical adhesiolysis was performed. The animals were then allocated to one of two equal groups, a control group without further intervention and a group receiving 1-ml ultrapure alginate gel to the two opposing and damaged surfaces. Two weeks after the second surgery, rats were sacrificed. Primary endpoint was the incidence of adhesion reformation at areas of injury. Secondary endpoints were adhesion scores, extent of adhesions, and tissue histology.
Ultrapure alginate gel significantly (p = 0.046) reduced the incidence of adhesion reformation from 100 % in controls to 78 % in experimental rats. Both the adhesion score (p = 0.009) and the extent of adhesions (p = 0.001) were significantly lower in the alginate group. Tissue healing histology was similar in both groups.
Ultrapure alginate gel reduces adhesion reformation following adhesiolysis.
International Journal of Colorectal Disease 09/2014; 29(11). DOI:10.1007/s00384-014-2009-5 · 2.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract Objective: The first international summit on anastomotic leak was held in Chicago in October, 2012 to assess current knowledge in the field and develop novel lines of inquiry. The following report is a summary of the proceedings with commentaries and future prospects for clinical trials and laboratory investigations. Background: Anastomotic leakage remains a devastating problem for the patient, and a continuing challenge to the surgeon operating on high-risk areas of the gastrointestinal tract such as the esophagus and rectum. Despite the traditional wisdom that anastomotic leak is because of technique, evidence to support this is weak-to-non-existent. Outcome data continue to demonstrate that expert high-volume surgeons working in high-volume centers continue to experience anastomotic leaks and that surgeons cannot predict reliably which patients will leak. Methods: A one and one-half day summit was held and a small working group assembled to review current practices, opinions, scientific evidence, and potential paths forward to understand and decrease the incidence of anastomotic leak. Results: Results of a survey of the opinions of the group demonstrated that the majority of participants believe that anastomotic leak is a complicated biologic problem whose pathogenesis remains ill-defined. The group opined that anastomotic leak is underreported clinically, it is not because of technique except when there is gross inattention to it, and that results from animal models are mostly irrelevant to the human condition. Conclusions: A fresh and unbiased examination of the causes and strategies for prevention of anastomotic leak needs to be addressed by a continuous working group of surgeons, basic scientists, and clinical trialists to realize a real and significant reduction in its incidence and morbidity. Such a path forward is discussed.
[Show abstract][Hide abstract] ABSTRACT: Background
Anastomotic leakage rates remain unacceptably high, warranting reconsideration of current anastomotic technique. Anastomotic healing may improve by abrading the serosal surface of bowel ends that are invertedly anastomosed, based on the concept that serosal damage evokes an inflammatory adherent processes. It is studied if local abrasion leads to stronger anastomoses and reduces leakage.
Ninety-eight Wistar rats were allocated to six groups. Either a regular anastomosis (RA) or abraded anastomosis (AA) was constructed in the proximal colon. Animals were sacrificed at day 3 (groups RA3 and AA3, n=2x17) or day 5 (groups RA5 and AA5, n=2x17). Groups RA-Dic and AA-Dic (n=2x15) received diclofenac from day 0 until sacrifice on day 3 to impair anastomotic healing. Outcomes were leakage, bursting pressure (BP), breaking strength (BS), adhesions and histological appearance.
Both in abraded (AA3, AA5) and control (RA3, RA5) groups without diclofenac 1 of 17 anastomoses leaked (6%). Leak rate was 9 of 15 (60%) in group AA-Dic and 8 of 15 (53%) in RA-Dic (p=1.0). The BP in group RA3 (127±44 mmHg) was higher (p=0,006) compared to group AA3 (82±34 mmHg), BS was comparable (p=0.331). Mechanical strength was similar between group RA5 and AA5. Abrasion did not increase mechanical strength in the diclofenac groups. Adhesion formation was not different between groups. Histology showed dense interserosal scar formation in abraded groups, compared to loose connective tissue in control anastomoses.
Abrasion of serosal edges of large bowel ends invertedly anastomosed does not improve anastomotic strength, neither does it reduce leakage in anastomoses compromised by diclofenac.
Journal of Surgical Research 09/2014; 193(2). DOI:10.1016/j.jss.2014.08.047 · 1.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Reduced intake and absorption of antioxidants due to pain and malabsorption are probable causes of the lower levels of antioxidants observed in patients with chronic pancreatitis (CP). Improving the status of antioxidants might be effective in slowing the disease process and reducing pain in CP.
[Show abstract][Hide abstract] ABSTRACT: Hydrogen sulfide (H2S) has become a molecule of high interest in recent years, and it is now recognized as the third gasotransmitter in addition to nitric oxide and carbon monoxide. In this review, we discuss the recent literature on the physiology of endogenous and exogenous H2S, focusing upon the protective effects of hydrogen sulfide in models of hypoxia and ischaemia. Linked ArticlesThis article is part of a themed section on Pharmacology of the Gasotransmitters. To view the other articles in this section visit
British Journal of Pharmacology 08/2014; 172(6). DOI:10.1111/bph.12869 · 4.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Syndecan-1 is a transmembrane heparan sulfate (HS) proteoglycan present on hepatocytes and involved in uptake of triglyceride-rich lipoproteins via its HS polysaccharide side chains. We hypothesized that altered hepatic syndecan-1 metabolism could be involved in dyslipidemia related to renal transplantation. In a rat renal transplantation model elevated plasma triglycerides were associated with fivefold increased expression of hepatic syndecan-1 mRNA (p < 0.01), but not protein. Expression of syndecan-1 sheddases (ADAM17, MMP9) and heparanase was significantly up-regulated after renal transplantation (all p < 0.05). Profiling of HS side chains revealed loss of hepatic HS upon renal transplantation accompanied by significant decreased functional capacity for VLDL binding (p = 0.02). In a human renal transplantation cohort (n = 510), plasma levels of shed syndecan-1 were measured. Multivariate analysis showed plasma syndecan-1 to be independently associated with triglycerides (p < 0.0001) and inversely with HDL cholesterol (p < 0.0001). Last, we show a physical association of syndecan-1 to HDL from renal transplant recipients (RTRs), but not to HDL from healthy controls. Our data suggest that after renal transplantation loss of hepatic HS together with increased syndecan-1 shedding hampers lipoprotein binding and uptake by the liver contributing to dyslipidemia. Our data open perspectives toward improvement of lipid profiles by targeted inhibition of syndecan-1 catabolism in renal transplantation.
American Journal of Transplantation 08/2014; 14(10). DOI:10.1111/ajt.12842 · 5.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Binding of renin and prorenin to the (pro)renin receptor (PRR) increases their enzymatic activity and upregulates the expression of pro-fibrotic genes in vitro. Expression of PRR is increased in the heart and kidney of hypertensive and diabetic animals, but its causative role in organ damage is still unclear. To determine whether increased expression of PRR is sufficient to induce cardiac or renal injury, we generated a mouse that constitutively overexpresses PRR by knocking-in the Atp6ap2/PRR gene in the hprt locus under the control of a CMV immediate early enhancer/chicken beta-actin promoter. Mice were backcrossed in the C57Bl/6 and FVB/N strain and studied at the age of 12 months. In spite of a 25- to 80-fold renal and up to 400-fold cardiac increase in Atp6ap2/PRR expression, we found no differences in systolic blood pressure or albuminuria between wild-type and PRR overexpressing littermates. Histological examination did not show any renal or cardiac fibrosis in mutant mice. This was supported by real-time PCR analysis of inflammatory markers as well as of pro-fibrotic genes in the kidney and collagen in cardiac tissue. To determine whether the concomitant increase of renin would trigger fibrosis, we treated PRR overexpressing mice with the angiotensin receptor-1 blocker losartan over a period of 6 weeks. Renin expression increased eightfold in the kidney but no renal injury could be detected. In conclusion, our results suggest no major role for PRR in organ damage per se or related to its function as a receptor of renin.Laboratory Investigation advance online publication, 21 July 2014; doi:10.1038/labinvest.2014.83.
[Show abstract][Hide abstract] ABSTRACT: Abdominal compartment syndrome (ACS) is a lethal complication of acute pancreatitis. We performed a systematic review to assess the treatment and outcome of these patients.A systematic literature search for cohorts of patients with acute pancreatitis and ACS was performed. The main outcomes were number of patients with ACS, radiologic and surgical interventions, morbidity, mortality, and methodological quality.After screening 169 articles, 7 studies were included. Three studies were prospective and 4 studies were retrospective. The overall methodological quality of the studies was moderate to low. The pooled data consisted of 271 patients, of whom 103 (38%) developed ACS. Percutaneous drainage of intraabdominal fluid was reported as first intervention in 11 (11%) patients. Additional decompressive laparotomy was performed in 8 patients. Decompressive laparotomy was performed in a total of 76 (74%) patients. The median decrease in intraabdominal pressure was 15 mm Hg (range, 33-18 mm Hg). Mortality in acute pancreatitis patients with ACS was 49% versus 11% without ACS. Morbidity ranged from 17% to 90%.Abdominal compartment syndrome during acute pancreatitis is associated with high mortality and morbidity. Studies are relatively small and have methodological shortcomings. The optimal timing and method of invasive interventions, as well as their effect on clinical outcomes, should be further evaluated.
[Show abstract][Hide abstract] ABSTRACT: Each year millions of people sustain traumatic or surgical wounds, which require proper closure. Conventional closure techniques, including suturing and stapling, have many disadvantages. They inflict additional damage on the tissue, elicit inflammatory responses and have a relatively long application time. Especially for the more demanding wounds, where fluids or gasses are to be sealed off, these techniques are often insufficient. Therefore, a large variety of tissue adhesives, sealants and hemostatic agents has been developed. This review provides an overview of such tissue adhesive materials from a polymer chemistry perspective. The materials are divided into synthetic polymer-based, polysaccharide-based and protein-based adhesives. Their specific properties and behavior are discussed and related to their clinical application. Though each type has its specific advantages, yet few have become standard in clinical practice. Biomimetic based adhesives and other novel products have shown promising results but also face specific problems. For now, the search for better adhering, stronger, easier applicable and cheaper adhesives continues and this review is intended as starting point and inspiration for these future research efforts to develop the next generation tissue adhesives.
[Show abstract][Hide abstract] ABSTRACT: Objective: To evaluate the safety and long-term durability of 1-stage repair of enteric fistulas in the presence of an abdominal wall defect. Background: Patients with enteric fistulas and an abdominal wall defect present an extreme challenge to surgeons and have been associated with significant morbidity and mortality. Durability of repair is unknown as studies fail to report this or use limited follow-up periods. Methods: Chart review was done of consecutive patients who underwent 1-stage repair. Short-term outcomes included morbidity (wound and medical) and mortality. Long-term durability of repair was determined by prospective outpatient follow-up at least 3 years after surgery. Results: Thirty-nine patients were included with a mean age of 61.2 years, a mean BMI of 24.4 kg/m2, and a mean abdominal wall defect size of 247.9 cm2. Component separation technique was used in 34 (87.2%) and synthetic mesh in 13 (33.3%) patients. There was 1 (2.6%) postoperative death. Twenty-four wound complications developed in 18 (46.2%) patients, including surgical-site infection in 8 (20.5%) patients. Two (5.1%) enteric fistulas recurred and were treated conservatively resulting in closure. Medical complications were seen 36 times in 23 (59%) patients. Twelve of 33 (36.4%) living patients developed a recurrent hernia after a mean follow-up of 62.7 months (range: 36–130). Conclusions: One-stage abdominal wall reconstruction with enteric fistula takedown is feasible at the cost of considerable morbidity. Our treatment strategy including component separation technique with synthetic mesh on-demand results in a durable repair in 6 to 7 of 10 patients.
Annals of Surgery 06/2014; 261(3). DOI:10.1097/SLA.0000000000000733 · 8.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Preeclampsia is characterized by deficient trophoblast invasion and spiral artery remodeling, a process governed by inflammatory cells. High levels of the danger signal extracellular adenosine triphosphate (ATP) have been found in women with preeclampsia and infusion of ATP in pregnant rats induced preeclampsia-like symptoms such as albuminuria and placental ischemia. We hypothesized that ATP inhibits trophoblast invasion and spiral artery remodeling and affects macrophages and natural killer (NK) cells present in the rat mesometrial triangle.
[Show abstract][Hide abstract] ABSTRACT: At least 30% of patients with infected necrotizing pancreatitis are successfully treated with catheter drainage alone. It is currently not possible to predict which patients also need necrosectomy. We evaluated predictive factors for successful catheter drainage.
This was a post hoc analysis of 130 prospectively included patients undergoing catheter drainage for (suspected) infected necrotizing pancreatitis. Using logistic regression, we evaluated the association between success of catheter drainage (ie, survival without necrosectomy) and 22 factors regarding demographics, disease severity (eg, Acute Physiology And Chronic Health Evaluation II score, organ failure), and morphologic characteristics on computed tomography (eg, percentage of necrosis).
Catheter drainage was performed percutaneously in 113 patients and endoscopically in 17 patients. Infected necrosis was confirmed in 116 patients (89%). Catheter drainage was successful in 45 patients (35%). In multivariable regression, the following factors were associated with a reduced chance of success: male sex [odds ratio (OR) = 0.27; 95% confidence interval (CI): 0.09-0.55; P < 0.01], multiple organ failure (OR = 0.15; 95% CI: 0.04-0.62; P < 0.01), percentage of pancreatic necrosis (<30%/30%-50%/>50%: OR = 0.54; 95% CI: 0.30-0.96; P = 0.03), and heterogeneous collection (OR = 0.21; 95% CI: 0.06-0.67; P < 0.01). A prediction model incorporating these factors demonstrated an area under the receiver operating characteristic curve of 0.76. A prognostic nomogram yielded success probability of catheter drainage from 2% to 91%.
Male sex, multiple organ failure, increasing percentage of pancreatic necrosis and heterogeneity of the collection are negative predictors for success of catheter drainage in infected necrotizing pancreatitis. The constructed nomogram can guide prognostication in clinical practice and risk stratification in clinical studies.
[Show abstract][Hide abstract] ABSTRACT: Background and purpose:
Hypertension is an important mediator of cardiac damage and remodelling. Hydrogen sulfide (H2S) is an endogenously produced gasotransmitter with cardioprotective properties. However, it is not yet in clinical use. We, therefore, investigated the protective effects of sodium thiosulfate (STS), a clinically applicable H2 S donor substance, in angiotensin II (Ang II)-induced hypertensive cardiac disease in rats.
Male Sprague Dawley rats were infused with Ang II (435 ng kg min(-1)) or saline (control) for 3 weeks via s.c. placed osmotic minipumps. During these 3 weeks, rats received i.p. injections of either STS, NaHS or vehicle (0.9% NaCl).
Compared with controls, Ang II infusion caused an increase in systolic and diastolic BP with associated cardiac damage as evidenced by cardiac hypertrophy, an increase in atrial natriuretic peptide (ANP) mRNA, cardiac fibrosis and increased oxidative stress. Treatment with NaHS and STS prevented the development of hypertension and the increase in ANP mRNA levels. Furthermore, the degree of cardiac hypertrophy, the extent of histological fibrosis in combination with the expression of profibrotic genes and the levels of oxidative stress were all significantly decreased.
Conclusions and implications:
Ang II-induced hypertensive cardiac disease can be attenuated by treatment with STS and NaHS. Although BP regulation is the most plausible mechanism of cardiac protection, the antifibrotic and antioxidant properties of released sulfide may also contribute to their effects. Our data show that H2 S might be a valuable addition to the already existing antihypertensive and cardioprotective therapies.
British Journal of Pharmacology 06/2014; 172(6). DOI:10.1111/bph.12825 · 4.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The peritoneum is one of the commonest sites for pathological processes in pediatric surgery. Its response to pathological processes is characterized by an inflammatory reaction with specific pathways depending on the type of injury or peritoneal process involved. This review discusses the current understanding of peritoneal inflammation, adhesion formation, intra-abdominal sepsis, peritoneal metastasis, and ascites and briefly reviews new therapeutic strategies to treat or prevent these pathological entities. Recent studies have improved the understanding of peritoneal responses, resulting in possible new targets for prevention and therapy.
Seminars in Pediatric Surgery 06/2014; 23(6). DOI:10.1053/j.sempedsurg.2014.06.003 · 2.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract Background. The lack of pathognomonic findings and the chance of complicated disease have resulted in the widespread use of additional imaging to diagnose acute colonic diverticulitis (ACD). The added value of additional imaging in the diagnostic workup of patients suspected of ACD is not well defined. Aims. The aim of this study was to systematically review the literature of the accuracy of the clinical evaluation and diagnostic modalities for patients with suspected ACD, to come to an evidence-based approach to diagnose ACD. Methods. A systematic review and meta-analysis of studies that reported diagnostic accuracy of the clinical diagnosis and diagnostic modalities in patients with suspected diverticulitis were performed. Study quality was assessed with the STARD checklist. True-positive, true-negative, false-positive, and false-negative findings were extracted and pooled estimates of sensitivity and specificity per diagnostic test were calculated, if applicable. Results. The overall quality of the studies reporting the diagnostic accuracy of the clinical diagnosis, contrast enema and magnetic resonance imaging (MRI) were moderate to poor and not suitable for meta-analysis. Sensitivity of the clinical diagnosis varied between 64% and 68%. Ultrasound (US) and computed tomography (CT) studies were eligible for meta-analysis. Summary sensitivity estimates for US were 90% (95% CI: 76-98%) versus 95% (95% CI: 91-97%) for CT (p = 0.86). Summary specificity estimates for US were 90% (95% CI: 86-94%) versus 96% (95% CI: 90-100%) for CT (p = 0.04). Sensitivity for MRI was 98% and specificity varied between 70% and 78%. Sensitivity of contrast enema studies varied between 80% and 83%. Conclusion. In two-thirds of the patients, the diagnosis of ACD can be made based on clinical evaluation alone. In one-third of the patients, additional imaging is a necessity to establish the diagnosis. US and CT are comparable in diagnosing diverticulitis and superior to other modalities. CT has the advantage of higher specificity and the ability to identify alternative diagnoses. The role of MRI is not yet clear in diagnosing ACD. Contrast enema is considered an obsolete imaging technique to diagnose ACD based on lower sensitivity and specificity than US and CT. A step-up approach with CT performed after an inconclusive or negative US, seems a logical and safe approach for patients suspected of ACD.
[Show abstract][Hide abstract] ABSTRACT: Background:
Preoperative differentiation between malignant and benign pancreatic tumors can be difficult. Consequently, a proportion of patients undergoing pancreatoduodenectomy for suspected malignancy will ultimately have benign disease. The aim of this study was to compare preoperative clinical and diagnostic characteristics of patients with unexpected benign disease after pancreatoduodenectomy with those of patients with confirmed (pre)malignant disease.
We performed a multicenter retrospective cohort study in 1,629 consecutive patients undergoing pancreatoduodenectomy for suspected malignancy between 2003 and 2010 in 11 Dutch centers. Preoperative characteristics were compared in a benign:malignant ratio of 1:3. Malignant cases were selected from the entire cohort by using a random number list. A multivariable logistic regression prediction model was constructed to predict benign disease.
Of 107 patients (6.6 %) with unexpected benign disease after pancreatoduodenectomy, 86 fulfilled the inclusion criteria and were compared with 258 patients with (pre)malignant disease. Patients with benign disease presented more often with pain (56 vs. 38 %; P = 0.004), but less frequently with jaundice (60 vs. 80 %; P < 0.01), a pancreatic mass (13 vs. 54 %, P < 0.001), or a double duct sign on computed tomography (21 vs. 47 %; P < 0.001). In a prediction model using these parameters, only 19 % of patients with benign disease were correctly predicted, and 1.4 % of patients with malignant disease were missed.
Nearly 7 % of patients undergoing pancreatoduodenectomy for suspected malignancy were ultimately diagnosed with benign disease. Although some preoperative clinical and imaging characteristics might indicate absence of malignancy, their discriminatory value is insufficient for clinical use.