Characteristics of different mesh types for abdominal wall repair in an experimental model of peritonitis.

BACKGROUND: The use of synthetic mesh to repair a potentially contaminated incisional hernia may lead to higher failure rates. A biological mesh might be considered, but little is known about long-term results. Both biological and synthetic meshes were investigated in an experimental model of peritonitis to assess their characteristics in vivo. METHODS: Male Wistar rats were randomized into five groups and peritonitis was induced. A mesh was implanted after 24 h. Five meshes were investigated: Permacol™ (cross-linked collagen), Strattice™ (non-cross-linked collagen), XCM Biologic® (non-cross-linked collagen), Omyra® Mesh (condensed polytetrafluoroethylene) and Parietene™ (polypropylene). The rats were killed after either 30, 90 or 180 days. Incorporation and shrinkage of the mesh, adhesion coverage, strength of adhesions and histology were analysed. RESULTS: Of 135 rats randomized, 18 died from peritonitis. Some 180 days after implantation, both XCM Biologic® and Permacol™ had significantly better incorporation than Strattice™ (P = 0·003 and P = 0·009 respectively). Strattice™ had significantly fewer adhesions than XCM Biologic® (P = 0·001) and Permacol™ (P = 0·020). Thirty days after implantation, Permacol™ had significantly stronger adhesions than Strattice™ (P < 0·001). Shrinkage was most prominent in XCM Biologic® , but no significant difference was found compared with the other meshes. Histological analysis revealed marked differences in foreign body response among all meshes. CONCLUSION: This experimental study suggested that XCM Biologic® was superior in terms of incorporation, macroscopic mesh infection, and histological parameters such as collagen deposition and neovascularization. There must be sufficient overlap of mesh during placement, as XCM Biologic® showed a high rate of shrinkage. Surgical relevance The use of synthetic mesh to repair a potentially contaminated incisional hernia is not supported unequivocally, and may lead to a higher failure rate. A biological mesh might be considered as an alternative. There are few long-term studies, as these meshes are expensive and rarely used. This study evaluated the use of biological mesh in a contaminated environment, and investigated whether there is an ideal mesh. A new non-cross-linked biological mesh (XCM Biologic® ) was evaluated in this experiment. The new non-cross-linked biological mesh XCM Biologic® performed best and may be useful in patients with a potentially contaminated incisional hernia.

In vitro model to study the biomaterial-dependent reaction of macrophages in an inflammatory environment.

BACKGROUND: Macrophages play an important role in the reaction to biomaterials, which sometimes have to be used in a surgical field at risk of contamination. The macrophage phenotype in reaction to biomaterials in an inflammatory environment was evaluated in both an in vivo and in vitro setting. METHODS: In the in vivo setting, polypropylene (PP) biomaterial was implanted for 28 days in the contaminated abdominal wall of rats, and upon removal analysed by routine histology as well as immunohistochemistry for CD68 (marker for macrophages), inducible nitric oxide synthase (iNOS - a marker for proinflammatory M1 macrophages) and CD206 (marker for anti-inflammatory M2 macrophages). For the in vitro model, human peripheral blood monocytes were cultured for 3 days on biomaterials made from PP, collagen (COL), polyethylene terephthalate (PET) and PET coated with collagen (PET+COL). These experiments were performed both with and without lipopolysaccharide and interferon γ stimulation. Secretion of both M1- and M2-related proteins was measured, and a relative M1/M2 index was calculated. RESULTS: In vivo, iNOS- and CD206-positive cells were found around the fibres of the implanted PP biomaterial. In vitro, macrophages on both PP and COL biomaterial had a relatively low M1/M2 index. Macrophages on the PET biomaterial had a high M1/M2 index, with the highest increase of M1 cytokines in an inflammatory environment. Macrophages on the PET+COL biomaterial also had a high M1/M2 index. CONCLUSION: Macrophages in an inflammatory environment in vitro still react in a biomaterial-dependent manner. This model can help to select biomaterials that are tolerated best in a surgical environment at risk of contamination.

Early experience with laparoscopic lavage for perforated diverticulitis.

BACKGROUND: Laparoscopic lavage has recently emerged as a promising alternative to sigmoid resection in the treatment of perforated diverticulitis. This study examined an early experience with this technique. METHODS: The files of all patients with complicated diverticulitis were searched in 34 teaching hospitals of the Netherlands. Patients with perforated diverticulitis treated with laparoscopic lavage between 1 January 2008 and 31 December 2010 were included. RESULTS: Treatment with laparoscopic lavage was performed in only 38 patients in ten hospitals. Lavage was successful in controlling sepsis in 31 of the 38 included patients, with 32 per cent morbidity (10 of 31 patients) and fast recovery. Overall, 17 of 38 patients developed complications, of whom two had a missed overt sigmoid perforation. Two patients died from multiple organ failure and one from aspiration pneumonia; one other patient died after palliative management of inoperable lung carcinoma. Three patients in whom lavage was successful underwent subsequent sigmoid resection for recurrent diverticulitis. Patients in whom lavage was unsuccessful tended to have more co-morbidities, a higher preoperative C-reactive protein concentration and a higher Mannheim Peritonitis Index. CONCLUSION: Laparoscopic lavage for perforated diverticulitis was feasible in the majority of patients, but identification of an overt sigmoid perforation and patient selection are of critical importance.

Prenatal ultrasound diagnosis of MYH7 non-compaction cardiomyopathy.

We report on two prenatal ultrasound diagnoses of left ventricular non-compaction cardiomyopathy (LVNC) associated with mutation of the cardiac ß-myosin heavy chain gene (MYH7). LVNC is characterized by a trabecular meshwork and deep intertrabecular myocardial recesses communicating with the left ventricular cavity. Clinical features range from non-penetrant disease in adult carriers to heart failure, arrhythmia and thromboembolism. Both cases showed cardiomegaly on prenatal ultrasound examinations, with features indicating non-compaction of the myocardium apparent in the third trimester. Mutations in the MYH7 gene were identified postnatally in each case in both the proband and the father. One infant underwent surgical mitral valvuloplasty and a mechanical valve implant later; in the other, left ventricular function was unimpaired at birth. Cardiac function in both cases remained stable at last follow-up. These cases highlight the importance of prenatal ultrasound diagnosis of LVNC and the need for cardiologic and molecular testing of first-degree relatives who may be unknown carriers of an MYH7 mutation.

Experimental study on synthetic and biological mesh implantation in a contaminated environment.

BACKGROUND: Implantation of meshes in a contaminated environment can be complicated by mesh infection and adhesion formation. METHODS: The caecal ligation and puncture model was used to induce peritonitis in 144 rats. Seven commercially available meshes were implanted intraperitoneally: six non-absorbable meshes, of which three had an absorbable coating, and one biological mesh. Mesh infection, intra-abdominal abscess formation, adhesion formation, incorporation and shrinkage were evaluated after 28 and 90 days. Histological examination with haematoxylin and eosin and picrosirius red staining was performed. RESULTS: No mesh infections occurred in Sepramesh(®) , Omyramesh(®) and Strattice(®) . One mesh infection occurred in Parietene(®) and Parietene Composite(®) . Significantly more mesh infections were found in C-Qur(®) (15 of 16; P ≤ 0·006) and Dualmesh(®) (7 of 15; P ≤ 0·035). Sepramesh(®) showed a significant increase in adhesion coverage from 12·5 per cent at 28 days to 60·0 per cent at 90 days (P = 0·010). At 90 days there was no significant difference between median adhesion coverage of Parietene Composite(®) (35·0 per cent), Omyramesh(®) (42·5 per cent), Sepramesh(®) (60·0 per cent) and Parietene(®) (72·5 per cent). After 90 days the adhesion coverage of Strattice(®) was 5·0 per cent, and incorporation (13·4 per cent) was significantly poorer than for other non-infected meshes (P ≤ 0·009). Dualmesh(®) showed shrinkage of 63 per cent after 90 days. CONCLUSION: Parietene Composite(®) and Omyramesh(®) performed well in a contaminated environment. Strattice(®) had little adhesion formation and no mesh infection, but poor incorporation. Some synthetic meshes can be as resistant to infection as biological meshes.

Systematic review of trocar-site hernia.

BACKGROUND: Broad implementation of laparoscopic surgery has made trocar-related complications clinically important. Trocar-site hernia (TSH) is an uncommon, but potentially serious, complication that occasionally requires emergency surgery. This systematic review was conducted to establish the prevalence and risk factors for TSH. METHODS: The review was conducted according to the PRISMA guidelines. MEDLINE, Embase, Web of Science and the Cochrane Library were searched to 7 June 2010 for studies on TSH. RESULTS: Twenty-two articles were included. One study was a randomized clinical trial, five were prospective cohort studies and 16 were retrospective cohort studies. The prevalence of TSH is low, with a median pooled estimate of 0·5 (range 0-5·2) per cent. No meta-analysis on risk factors could be performed. Pyramidal trocars, 12-mm trocars and a long duration of surgery were identified as the most important technical risk factors for TSH. Older age and a higher body mass index were observed to be patient-related risk factors. CONCLUSION: TSH is an uncommon complication of laparoscopic surgery. The most important technical risk factors are the design and size of the trocars. The scientific evidence for recommendations to avoid TSH is sparse.

Postoperative adhesion prevention with a new barrier: an experimental study.

INTRODUCTION: Postoperative adhesion formation remains a major clinical problem. The aim of this study was to test the effect of a new hydrogel on adhesion formation in a rat model. MATERIALS AND METHODS: A reproducible rat model was used to induce standardized adhesion formation in three experiments. In experiment 1, a cross-linked polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) hydrogel (PVA/CMC, A-Part®; B. Braun Aesculap, Germany) was tested in different dosages. In experiment 2, PVA/CMC gel was compared to icodextrin 4% (Adept®; Baxter USA). In both groups, animals were sacrificed after 2 weeks. In experiment 3, histological examination after 4 and 6 weeks was performed. The percentage of adhesions to the defect was measured and the density was determined according to the Zühlke scale. During histological examination of the abdominal wall, the formation of neoperitoneum and potential residues of the agents were assessed. RESULTS: In experiment 1, a significant reduction in amount as well as density of the adhesions was visible with all dosages of PVA/CMC gel. In experiment 2, again quantity and density of the adhesions were diminished by PVA/CMC hydrogel compared to the control group. Icodextrin 4% showed no significant reduction in adhesion formation. In experiment 3, no residues of PVA/CMC gel or icodextrin 4% were found during histological examination after 4 and 6 weeks and neoperitoneum was present in all cases. CONCLUSION: PVA/CMC hydrogel appears to be a novel effective adhesion prevention agent. Together with an upcoming safety study, these data encourage to start clinical efficacy studies.

Preoperative staging of perforated diverticulitis by computed tomography scanning.

BACKGROUND: Treatment of perforated diverticulitis depends on disease severity classified according to Hinchey's preoperative classification. This study assessed the accuracy of preoperative staging of perforated diverticulitis by computerized tomography (CT) scanning. METHODS: All patients who presented with perforated diverticulitis between 1999 and 2009 in two teaching hospitals of Rotterdam, the Netherlands, and in addition had a preoperative CT scan within 24 h before emergency surgery were included. Two radiologists reviewed all CT scans and were asked to classify the severity of the disease according to the Hinchey classification. The CT classification was compared to Hinchey's classification at surgery. RESULTS: Seventy-five patients were included, 48 of whom (64 %) were classified Hinchey 3 or 4 perforated diverticulitis during surgery. The positive predictive value of preoperative CT scanning for different stages of perforated diverticulitis ranged from 45 to 89 %, and accuracy was between 71 and 92 %. The combination of a large amount of free intra-abdominal air and fluid was strongly associated with Hinchey 3 or 4 and therefore represented a reliable indicator for required surgical treatment. CONCLUSIONS: The accuracy of predicting Hinchey's classification by preoperative CT scanning is not very high. Nonetheless, free intra-abdominal air in combination with diffuse fluid is a reliable indication for surgery as it is strongly associated with perforated diverticulitis with generalized peritonitis. In 42 % of cases, Hinchey 3 perforated diverticulitis is falsely classified as Hinchey 1 or 2 by CT scanning.

Cardiac evaluation in children and adults with Pompe disease sharing the common c.-32-13T>G genotype rarely reveals abnormalities.

BACKGROUND AND OBJECTIVE: Pompe disease is an inherited metabolic disorder caused by deficiency of acid alpha-glucosidase. All affected neonates have a severe hypertrophic cardiomyopathy, leading to cardiac failure and death within the first year of life. We investigated the presence and extent of cardiac involvement in children and adults with Pompe disease with the common c.-32-13T>G genotype to determine the usefulness of cardiac screening in these patients with relatively 'milder' phenotypes. METHODS: Cardiac dimensions and function were evaluated through echocardiography, electrocardiography and Holter monitoring. The total group comprised 68 patients with Pompe disease, of whom 22 patients had disease onset before the age of 18. RESULTS: Two patients (3%) had cardiac abnormalities possibly related to Pompe disease: Electrocardiography showed a Wolff-Parkinson-White pattern in an 8-year-old girl, and one severely affected adult patient had a mild hypertrophic cardiomyopathy. This hypertrophy did not change during treatment with recombinant human alpha-glucosidase. In addition, four adult patients showed minor cardiac abnormalities which did not exceed the prevalence in the general population and were attributed to advanced age, hypertension or pre-existing cardiac pathology unrelated to Pompe disease. CONCLUSIONS: Cardiac involvement is rare in Pompe patients with the common c.-32-13T>G genotype. The younger patients were not more frequently affected than the adults. Electrocardiographic evaluation appears to be appropriate as initial screening tool. Extensive cardiac screening seems indicated only if the electrocardiogram is abnormal or the patient has a history of cardiac disease.

Improvements in gel composition and electrophoretic conditions for broad-range mutation analysis by denaturing gradient gel electrophoresis.

Denaturing gradient gel electrophoresis (DGGE) is believed to be the most powerful pre-screening method for mutation detection currently available, being used mostly on an exon-by-exon basis. Broad-range DGGE for the analysis of multiple fragments or an entire gene is rarely applied. We and others have already shown that one or two DGGE conditions are usually sufficient to analyse an entire gene. Conditions, however, have never been profoundly tested and compared with alternative methods suggested in the literature. Trying to do so in this study, we found significant differences between the various gel systems. The optimal conditions we found for broad-range DGGE include 9% polyacrylamide for the gel, a denaturing gradient with a difference of 30-50% between the lowest and the highest concentration of denaturant, and electrophoresis in 0.5x TAE buffer at a voltage >100 V and <200 V.

Fluorinated steroids do not improve outcome of isolated atrioventricular block.

INTRODUCTION: Congenital atrioventricular block (CAVB) is a rare disorder with a significant morbidity and mortality. Consensus regarding the prescription and efficacy of prenatal corticosteroids is lacking. This nationwide study was initiated to evaluate the effects of prenatal treatment with corticosteroids on the outcome of CAVB in The Netherlands. METHODS: All fetuses identified with isolated congenital AVB-II° or AVB-III° in any of the eight academic fetal heart centers of The Netherlands between 2003 and 2013 were included and reviewed. RESULTS: Fifty-six fetuses were included. Fourteen (25%) fetuses were treated with dexamethasone. We found no differences between the steroid-treated and untreated cases regarding in utero progression of the AVB (63% vs 67% respectively), survival to birth (86% vs 84%), pacemaker implantations (74% vs 58%) or long-term dilated cardiomyopathy (13% vs 17%). Steroid treated fetuses demonstrated more in utero growth restriction (38% vs 11%). CONCLUSION: No benefit from prenatal corticosteroid treatment was demonstrated for fetuses with isolated CAVB in this study. However, we found negative side effects. Our data provide no evidence to support the routine administration of corticosteroids for the treatment of fetal CAVB.

Management of fixed subaortic stenosis: a retrospective study of 57 cases.

Although recommended by several investigators, the benefit of early surgery in patients with fixed subaortic stenosis has not been proved. Findings were reviewed of 57 patients with isolated fixed subaortic stenosis, including 27 surgically treated patients, with special emphasis on the occurrence of aortic regurgitation during a mean follow-up period of 6.7 years. The number of patients with aortic regurgitation increased preoperatively in the total group (23% at diagnosis to 54% after 3.7 years of follow-up). The prevalence of aortic regurgitation in the 27 surgically treated patients was higher (81%) than that in the nonsurgically treated group but remained unchanged after a mean postoperative period of 4.7 years. In all patients but one, aortic regurgitation remained of minor hemodynamic significance. One patient died during follow-up. After surgery, 15 patients (55%) showed a relapse; 11 redeveloped a subvalvular pressure gradient greater than 30 mm Hg and discrete subvalvular ridges (range 6 months to 24 years after surgery, mean 7 years). In those patients with fixed subaortic stenosis, follow-up did not reveal any benefit from early surgery. The unpredictable course and sometimes very severe progression of this disease make frequent and careful follow-up necessary.

Clinical significance of maternal anti-Ro/SS-A antibodies in children with isolated heart block.

OBJECTIVES: We studied 30 consecutive children with isolated heart block to assess the clinical impact of the presence of maternal anti-Ro/SS-A antibodies for isolated heart block. BACKGROUND: Isolated heart block in children, often associated with maternal autoimmune disease leading to anti-Ro/SS-A auto-antibody production, is an infrequent but potentially lethal disorder. METHODS: Thirty children with isolated heart block were studied with respect to medical history and electrocardiographic (ECG) analysis. The presence of anti-Ro/SS-A antibodies was determined in the maternal serum. We also examined the ECGs of all brothers and sisters of the patients for conduction abnormalities. RESULTS: Twenty-one of the 30 children had an anti-Ro/SS-A-positive mother (group A); the other 9 children had an anti-Ro/SS-A-negative mother (group B). Comparison of the clinical data from both mothers and children revealed that these two groups differed significantly with respect to the following: Prenatal diagnosis and obstetric complications occurred more often in group A, whereas progression to complete block, QRS width > 0.08 s, premature ventricular contractions and ventricular standstills > 4.5 s occurred more often in group B. In addition, mothers of children in group A reported more spontaneous abortions. All siblings of children in groups A and B had normal ECGs, excluding a subclinical form of heart block. CONCLUSIONS: Two types of heart block can be recognized: Congenital heart block is associated with maternal anti-Ro/SS-A antibodies and numerous obstetric and neonatal complications. It is diagnosed prenatally or at birth and is usually complete at onset and probably has a substantial recurrence risk. Heart block that is acquired later in life is not associated with maternal autoimmunity and has no risk for recurrence. It often presents as a partial block but progresses to complete block in time.

Short- and midterm results of balloon valvuloplasty for valvular aortic stenosis in children.

During a 27-month period, 21 consecutive children (aged 0.1 to 15.7 years) with isolated valvular aortic stenosis underwent percutaneous transfemoral balloon valvuloplasty. Ten children had undergone earlier surgical valvulotomy. The indication for treatment was ST-T-segment changes at rest or during bicycle-ergometry, a continuous-wave Doppler-derived transvalvular gradient greater than 60 mm Hg or syncope, or a combination. Mean peak systolic left ventricular pressure decreased from 165 +/- 19 to 131 +/- 19 mm Hg (p less than 0.001). Mean end-diastolic left ventricular pressure did not change significantly (12 +/- 3 vs 11 +/- 5 mm Hg). Mean peak systolic valve gradient decreased from 71 +/- 23 to 22 +/- 11 mm Hg (p less than 0.001). Mean cardiac index remained unchanged (2.9 +/- 0.8 vs. 3.0 +/- 0.7 liters.min-1.m-2). Aortic valve regurgitation on angiography appeared or increased in 9 patients (up to grade 3 in 3 children). Noninvasive follow-up studies were performed for 2 to 4.2 years (mean 2.8). ST-T changes on the electrocardiogram at rest or during exercise were present in 6 patients before balloon valvuloplasty and had disappeared in all at 6-month follow-up. Reoccurrence of ST-T changes after a longer follow-up was associated with severe valve regurgitation. Syncope was not observed after balloon valvuloplasty. The continuous-wave Doppler gradient decreased from 94 +/- 36 to 49 +/- 15 mm Hg (p less than 0.001). After a follow-up of 2 to 4.2 years (mean 2.8) it remained unchanged (43 +/- 13 mm Hg; p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Chromosome 22q11 deletions in patients with selected outflow tract malformations.

The incidence of 22q11 deletions and its effect on the phenotype were established in 170 patients with selected outflow tract malformations and transposition of the great arteries (conotruncal defects). Cases were seen both prospectively and retrospectively. All patients had a dysmorphological evaluation by the clinical geneticist and a cytogenetic analysis including FISH analysis for 22q11 deletions. A chromosomal abnormality was present in 29 patients, including a 22q11 deletion in 22/170 patients (13%). The 22q11 deletion was found in 11% of tetralogy of Fallot, in 11% of pulmonary atresia and VSD, in 44% of pulmonary atresia. VSD and collateral arteries, in 20% of truncus arteriosus, in 60% of interrupted aortic arch and in 25% patients with aberrant subclavian artery. They were absent in double outlet right ventricle or in transposition of the great arteries. No parental deletion was found. All patients had clinical characteristics of the velocardiofacial syndrome. This study confirms a high incidence of chromosome 22q11 deletions in patients with selected outflow tract malformations, with great clinical impact for further management and genetic counseling.

[Surgical treatment of hypoplastic left heart syndrome: limited success]. / De operatieve behandeling van het hypoplastisch linkerhartsyndroom: beperkt succes.

OBJECTIVE: To inventory the treatment of hypoplastic left heart syndrome (HLHS) in the Netherlands and its results. DESIGN: Retrospective. METHOD: Data were collected from all patients (n = 117) diagnosed with HLHS in the Wilhelmina Children's Hospital-University Medical Center Utrecht and the University Hospital Rotterdam-Sophia Children's Hospital and born in the period 1 March 1988-31 May 2000. Type and time of intervention, and mortality were recorded and cumulative survival was analysed by Kaplan-Meier analysis. Cumulative survival was compared between early and late series and between the two hospitals. RESULTS: The study group comprised 68 boys and 49 girls, all neonates. At the time of the investigation, the mean duration of follow-up was 185 days (range: 0-3855). Fifty-eight children had received no treatment; all of these had died. Fifty-nine children were scheduled for the Norwood procedure; six of them died before operation. The 53 patients who underwent the first stage of the Norwood procedure had 1-month, 1-year, 2-year, and 5-year survival chances of 55%, 30%, 27%, and 24% respectively. Survival chances between the two time periods and the two hospitals showed no significant differences. CONCLUSION: The Norwood procedure was performed in almost half of the children with HLHS. It is only moderately successful; however, it seems the only realistic choice in the management.

[Glomerular filtration in premature infants]. / Glomerulusfiltratie bij prematuren.

Many methods for measuring glomerular filtration rate in preterm newborns are known. However only the classic inulin clearance as well as the continuous inulin infusion technique provide exact data, but are not easy to perform. In general pediatric practice the use of tables for 'normal values' of serum creatinine compared to serum creatinine levels of patients if useful.

Effect of enzyme therapy in juvenile patients with Pompe disease: a three-year open-label study.

Pompe disease is a rare neuromuscular disorder caused by deficiency of acid α-glucosidase. Treatment with recombinant human α-glucosidase recently received marketing approval based on prolonged survival of affected infants. The current open-label study was performed to evaluate the response in older children (age 5.9-15.2 years). The five patients that we studied had limb-girdle muscle weakness and three of them also had decreased pulmonary function in upright and supine position. They received 20-mg/kg recombinant human α-glucosidase every two weeks over a 3-year period. No infusion-associated reactions were observed. Pulmonary function remained stable (n = 4) or improved slightly (n = 1). Muscle strength increased. Only one patient approached the normal range. Patients obtained higher scores on the Quick Motor Function Test. None of the patients deteriorated. Follow-up data of two unmatched historical cohorts of adults and children with Pompe disease were used for comparison. They showed an average decline in pulmonary function of 1.6% and 5% per year. Data on muscle strength and function of untreated children were not available. Further studies are required.