Comparability of histological outcomes in rats and humans in a hernia model.

BACKGROUND: Hernia repair is one of the most frequently performed operations. In search of the ideal mesh for hernia repair, animal research is required. Although rats are most often used in experimental mesh experiments, no correlation with clinical findings in humans has ever been shown. Therefore, the aim of our study was to investigate whether adhesion formation and foreign body reactions to meshes in rats are comparable with the reactions in humans. MATERIALS AND METHODS: A fixed type of mesh was implanted intraperitoneally in a group of 10 rats and 10 patients undergoing elective, temporary stoma formation. In case of the latter, meshes were placed around the stoma. After a follow-up period of 12 wk in rats and after a median follow-up of 6 mo in humans, samples of the mesh were collected. Adhesion assessments were performed, and (immuno-) histochemical evaluation was performed by a specialized experimental pathologist and an experienced clinical pathologist. RESULTS: After the follow-up period, adhesion formation did not differ significantly between rats and humans. Moreover, general inflammation scores were comparable, although granulocytes and giant cells were more present in rats, compared with humans. On the other hand, the presence of fibrosis was more evident in humans compared with rats. CONCLUSIONS: To our knowledge, this is the first study, which showed that a specific animal model, namely a rat model, correlates with adhesion formation and the foreign body reaction to meshes in humans. It can be recommended to use rats in future experimental mesh for incisional hernia research.

Endoloops or endostapler use in laparoscopic appendectomy for acute uncomplicated and complicated appendicitis : No difference in infectious complications.

BACKGROUND: The most appropriate closure for the appendicular stump with either endoloops or an endostapler in laparoscopic appendectomy remains unclear and under debate because of limited and conflicting evidence. METHODS: In a 2-month prospective, observational, resident-led nationwide cohort study, patients undergoing laparoscopic appendectomy for both uncomplicated and complicated appendicitis were analysed. Logistic regression analyses were performed for identifying the possible effect of stump closure type and other risk factors for infectious complications. RESULTS: Laparoscopic appendectomy for acute appendicitis was performed in 1369 patients in 62 hospitals; endoloops were used in 76.7 % and an endostapler in other patients. Median operating time was not different between endoloop and endostapler use (42.0 vs. 44.0 min, P = 0.243). A superficial surgical site infection was seen in 2.0 % after uncomplicated appendicitis and in 0.8 % after complicated appendicitis. The intra-abdominal abscess rate was 1.9 % after uncomplicated and 11.0 % after complicated appendicitis. No significant effect of stump closure type was observed for any infectious complication (OR 1.05; 95 % CI 0.625-1.766, P = 0.853) or an intra-abdominal abscess (OR OR 0.96; 95 % CI 0.523-1.768, P = 0.899). In multivariable analysis, complicated appendicitis was identified as the only independent risk factor for an intra-abdominal abscess (OR 6.26; 95 % CI 3.454-11.341, P < 0.001). CONCLUSIONS: The infectious complication rate is not influenced by the type of appendicular stump closure with either endoloops or an endostapler in this study. If technically feasible, closure with endoloops is advised for cost considerations.

Prophylactic intraperitoneal mesh placement to prevent incisional hernia after stoma reversal: a feasibility study.

BACKGROUND: Incisional hernias in old stoma wounds occur in one-third of former stoma patients and pose a significant clinical problem. Parastomal hernias can be prevented by prophylactic mesh placement; however, no trial results are available for incisional hernia prevention after stoma reversal. In this feasibility study, we explore the safety of placing an intraperitoneal mesh to prevent incisional herniation after temporary stoma reversal. METHODS: Ten patients who underwent a low anterior resection with a deviating double-loop stoma for rectal cancer received an intraperitoneal parastomal mesh at the time of stoma formation. At stoma reversal, laparoscopy was performed and adhesions were scored. After reversal, the mesh defect was closed. Mesh and stoma complications were closely monitored. Incisional herniation was assessed at the 2-year follow-up after stoma reversal using ultrasonography. RESULTS: No infections occurred after mesh placement. After a median of 6 months, stomas were reversed. Laparoscopy could be performed in seven patients; all patients had adhesions (median of 25 % of mesh surface). In three patients, the bowel was involved; one required a laparotomy for bowel mobilization during stoma reversal. No adhesion-related morbidity was noted at any time. Except for one superficial wound infection after stoma reversal, no infectious complications were observed. After a median follow-up of 26 months, no incisional herniations were demonstrated. CONCLUSIONS: Prophylactic mesh placement in temporary stoma formations seems safe and feasible and prevents incisional herniation 2 years after stoma reversal.

Coated meshes for hernia repair provide comparable intraperitoneal adhesion prevention.

BACKGROUND: Laparoscopic incisional hernia repair with intraperitoneal mesh is associated with a certain degree of adhesion formation to the mesh. This experimental study examined the efficacy of several coated meshes for adhesion reduction. METHODS: Five commercially available meshes with a layered coating were placed intraperitoneally in rats and followed up for 90 days: polypropylene and polyester meshes, both coated with absorbable collagen (Parietene Composite and Parietex Composite, respectively), and three polypropylene meshes respectively coated with absorbable omega-3 fatty acids (C-Qur Edge), absorbable cellulose (Sepramesh IP), and nonabsorbable expanded polytetrafluoroethylene (Intramesh T1). Uncoated polypropylene and collagen meshs (Parietene and Permacol, respectively) served as the control condition. Adhesions, incorporation, and tissue reaction were evaluated macro- and microscopically. Additionally, the development of the neoperitoneum was examined. RESULTS: All the coated meshes performed equally well in terms of adhesion reduction. The collagen mesh performed comparably, but the uncoated polypropylene mesh performed significantly worse. The different coatings led to very differing degrees of inflammation. Ingrowth was observed only at the place of suture but was comparable for all the meshes except C-Qur Edge, which showed the weakest incorporation. Development of a neoperitoneum on the mesh surface occurred independently of whether an absorbable or nonabsorbable coating or no coating at all was present. CONCLUSIONS: Commercially available meshes with a layered coating deliver comparable adhesion reduction. The physical presence of a layered coating between the intraperitoneal content and the abdominal wall seems to be more important than the chemical properties of the coating in adhesion formation.

Enterotomy risk in abdominal wall repair: a prospective study.

OBJECTIVES: To establish the incidence and predictive factors of enterotomy made during adhesiolysis in abdominal wall repair and to assess the impact of enterotomies and long-lasting adhesiolysis on postoperative morbidity such as sepsis, wound infection, abdominal complications and pneumonia, and socioeconomic costs. BACKGROUND: Adhesions frequently complicate surgical repair of abdominal wall hernia. Enterotomies made during adhesiolysis specifically have a large impact on morbidity of patients, especially surgical site infections. Little is known on the incidence and burden of enterotomies and long-lasting adhesiolysis in abdominal wall repair. METHODS: Between June 2008 and June 2010 demographics, disease characteristics and perioperative data of all patients undergoing elective abdominal wall repair were included in a prospective cohort study that was focused on adhesiolysis-related problems. A trained researcher observed all surgeries and collected data on adhesion location, tenacity, adhesiolysis time, and inadvertent organ damage such as enterotomies. Primary outcome was the incidence of enterotomy, and predictive factors for enterotomy were assessed through univariate and multivariate analyses. In addition, we evaluated the impact of adhesiolysis and enterotomy on morbidity. RESULTS: A cohort of 133 abdominal wall repairs was analyzed. Adhesiolysis was required in 124 (93.2%), with a mean adhesiolysis time of 35.7 ± 29.8 minutes. Thirty-three enterotomies were made in 17 patients (12.8%). Two patients had a delayed diagnosed bowel perforation. Adhesiolysis time, hernia size greater than 10 cm, and fistula were significant predictive factors in univariate analysis. In multivariate analysis, only adhesiolysis time was a significant and independent predictive factor for enterotomy (P = 0.004). Trends toward an increased risk were seen for patients with mesh in situ and hernia size greater than 10 cm. Patients with enterotomy had significantly more urgent reoperations (P = 0.029), and they more often required parenteral feeding (P = 0.037). Moreover, patients with extensive adhesiolysis (adhesiolysis time, >30 minutes) more often suffered from wound infection (9/63 vs 2/70; P = 0.025), abdominal complications (5/63 vs 0/70; P = 0.022), and sepsis (4/63 vs 0/70; P = 0.048). CONCLUSIONS: One in 8 patients undergoing abdominal wall repair suffer inadvertent enterotomy following adhesiolysis. Adhesiolysis time predicts enterotomy. Morbidity in patients with extensive adhesiolysis and adhesiolysis complicated by enterotomy is high, inducing longer hospital stay and increased health care utilization.

Adhesion awareness: a national survey of surgeons.

BACKGROUND: Postoperative adhesions are the most frequent complication of abdominal surgery, leading to high morbidity, mortality, and costs. However, the problem seems to be neglected by surgeons for largely unknown reasons. METHODS: A survey assessing knowledge and personal opinion about the extent and impact of adhesions was sent to all Dutch surgeons and surgical trainees. The informed-consent process and application of antiadhesive agents were questioned in addition. RESULTS: The response rate was 34.4%. Two thirds of all respondents (67.7%) agreed that adhesions exert a clinically relevant, negative effect. A negative perception of adhesions correlated with a positive attitude regarding adhesion prevention (ρ = 0.182, p < 0.001). However, underestimation of the extent and impact of adhesions resulted in low knowledge scores (mean test score 37.6%). Lower scores correlated with more uncertainty about indications for antiadhesive agents which, in turn, correlated with never having used any of these agents (ρ = 0.140, p = 0.002; ρ = 0.095, p = 0.035; respectively). Four in 10 respondents (40.9%) indicated that they never inform patients on adhesions and only 9.8% informed patients routinely. A majority of surgeons (55.9%) used antiadhesive agents in the past, but only a minority (13.4%) did in the previous year. Of trainees, 82.1% foresaw an increase in the use of antiadhesive agents compared to 64.5% of surgeons (p < 0.001). CONCLUSIONS: The magnitude of the problem of postoperative adhesions is underestimated and informed consent is provided inadequately by Dutch surgeons. Exerting adhesion prevention is related to the perception of and knowledge about adhesions.

Adhesion awareness in 2016: An update of the national survey of surgeons.

BACKGROUND AND AIMS: Adhesions, that form in 60-80% of all abdominal operations, can cause complications such as chronic abdominal pain, small-bowel obstruction, female infertility, and the need for adhesiolysis in future surgeries. Our 2010 Adhesion Awareness survey demonstrated that despite the huge clinical impact of adhesions; adhesion-related complications were seldom mentioned in the informed consent. Six years later, a follow-up survey was conducted to assess the progress on awareness on adhesion-related complications in the Netherlands. MATERIAL AND METHODS: The 2010 Adhesion Awareness survey was repeated after a literature update. The knowledge regarding adhesions; the use of anti-adhesive agents and involvement in the informed consent process were assessed. Surgeons and surgical trainees were contacted by e-mail. The data was analysed using a Chi-square or Mann-Whitney U test and corrected for multiple testing. RESULTS: The response rate was 32.6%, similar to the survey in 2010 (34.4%). 88.1% agreed with the clinical relevance of adhesions, comparable to 2010 (89.8%). The score on the knowledge test was 38.8% (2010: 37.2%). Involvement of adhesion-related complications in the informed consent process increased, although 32.5% almost never mentions adhesions. In 2016, 42.4% reported a correct occurrence of bowel lesions during adhesiolysis, higher than in 2010 (P<0.001). CONCLUSIONS: The adhesion awareness did not increase in six years, despite the efforts made. However, an increased awareness regarding adhesiolysis related complications was detected. Improvement of knowledge and behavior is essential to narrowing the gap between the impact of adhesions as a major complication of abdominal surgery and the limited adhesion awareness.

Antibiotic Duration After Laparoscopic Appendectomy for Acute Complicated Appendicitis.

IMPORTANCE: Optimal duration of antibiotic treatment to reduce infectious complications after an appendectomy for acute complicated appendicitis remains unclear. OBJECTIVE: To investigate the effect of antibiotic duration on infectious complications after laparoscopic appendectomy for acute complicated appendicitis. DESIGN, SETTING, AND PARTICIPANTS: National multicenter prospective, observational, surgical resident-led cohort study conducted in June and July 2014. This study involved academic teaching hospitals (n = 8), community teaching hospitals (n = 38), and community nonteaching hospitals (n = 16), and all consecutive patients (n = 1975) who underwent surgery for suspected acute appendicitis. EXPOSURES: Patients treated laparoscopically for whom the antibiotic regimens were prolonged postoperatively because of complicated appendicitis. MAIN OUTCOMES AND MEASURES: Receiving either 3 or 5 days of antibiotic treatment as planned and additional variables were explored as risk factors for infectious complications using regression analyses. RESULTS: A total of 1975 patients were included in 62 participating Dutch hospitals; 1901 (96.3%) of these underwent an appendectomy for acute appendicitis and laparoscopy was used in 74.4% of these patients (n = 1415). In 415 laparoscopically treated patients, antibiotic treatment was continued for more than 24 hours because of acute complicated appendicitis (29.3%). The prescribed antibiotic duration varied between 2 and 6 days in all of these patients. In 123 patients (29.6%), the length of treatment was adjusted. A shorter duration of antibiotic treatment (3 days instead of 5) had no significant effect on any infectious complication (odds ratio [OR], 0.93; 95% CI, 0.38-2.32; P = .88) or on intra-abdominal abscess development (OR, 0.89; 95% CI, 0.34-2.35; P = .81). Perforation of the appendix was the only independent risk factor for the development of an infectious complication (OR, 4.90; 95% CI, 1.41-17.06; P = .01) and intra-abdominal abscess (OR, 7.46; 95% CI, 1.65-33.66; P = .009) in multivariable regression analysis. CONCLUSIONS AND RELEVANCE: Lengthening of postoperative antibiotic treatment to 5 days was not associated with a reduction in infectious complications. Further restriction of antibiotic treatment can be considered in nonperforated complicated appendicitis.

Postoperative abdominal adhesions and bowel obstruction. A survey among Dutch general practitioners.

BACKGROUND: There is increasing interest among specialists in the complications after abdominal surgery due to adhesions. OBJECTIVE: Exploration of experiences, attitudes and expectations of general practitioners concerning bowel obstruction and postoperative abdominal adhesions. METHODS: In October 2012 a postal questionnaire was sent to a random sample of 800 Dutch GPs. RESULTS: The response rate was 45%, 24% (n = 190) filled out the questionnaire completely, 12% (n = 99) had no experience with the subject and 7% (n = 57) had no time to respond. A history of abdominal surgery does play a part in more than 80% of GP's differential diagnosis of abdominal complaints. Seventy-five per cent consider some types of surgery to induce more adhesions. Eighty-five per cent ponder the differentiation between adhesion related complaints and IBS as clear, however difficult (78%) in specific patients. Intestinal transit problems likely due to adhesions are treated with extra fluid (n = 64), more fibres (n = 85) and laxatives (n = 153). Referral to a specialist for adhesiolysis is rarely considered (11%). Forty per cent of the GPs would refer a patient with abdominal pain and suspected adhesions. Seventy-six per cent denote knowledge gaps and low experience in the treatment of intestinal transit problems. Some (n = 23) indicate the need for information about adhesions and obstruction through CME papers. CONCLUSION: Respondents are well equipped to deal with abdominal complaints and intestinal transit problems due to postoperative adhesions. Some indicate the need for information about adhesions and prevention of obstruction through CME papers.

Adhesion awareness: a nationwide survey of gynaecologists.

OBJECTIVE: Adhesions and related complications lead to substantially increased morbidity and mortality which increase medical costs. We investigated the awareness of adhesions among Dutch gynaecologists and gynaecology residents. STUDY DESIGN: A survey, assessing knowledge and opinion about adhesions, was sent to a randomly selected group of 381 gynaecologists and 256 residents. In addition, the informed consent process and application of anti-adhesive agents were questioned. RESULTS: The response rate was 56.9%. Complications due to adhesions were highly underestimated, leading to low knowledge scores (mean score 35.1%). Of all respondents 73.8% agreed that adhesions exert a clinically relevant and negative effect, but only 51.2% expressed a positive opinion on adhesion prevention. This correlated with a stronger belief in the clinically relevant and negative effects of adhesions and the opinion that adhesion prevention belongs to standard care (ρ=0.212, p<0.001; ρ=0.495, p<0.001). Of all respondents 31.4% expressed a positive attitude towards anti-adhesive agents and 19.8% expressed a negative one. A negative attitude correlated with a negative view in terms of cost-benefits (ρ=0.245, p<0.001). Although 43.5% had used anti-adhesive agents in the past year, 20.9% had used them before but stopped using agents in the past year. Only 5.2% routinely included adhesions or related morbidity in the informed consent. CONCLUSIONS: Awareness of adhesions is limited and informed consent is provided inadequately. Implementing adhesion prevention is related with awareness of adhesions. These findings underline the need to embed adhesions, related morbidity and prevention in educational programmes.

Incisional hernias in temporary stoma wounds: a cohort study.

HYPOTHESIS: The prevalence of and risk factors for incisional hernias among temporary stoma wounds have implications for clinical practice. DESIGN: Retrospective cohort study. SETTING: University tertiary care hospital. PATIENTS: All adult patients with a stoma closed between January 1, 2000, and August 1, 2004. Of 150 living patients, 111 (74.0%) were included for analysis after follow-up at the outpatient clinic. MAIN OUTCOME MEASURES: The main outcome was incisional hernia in a temporary stoma wound, defined as a defect within the musculature and fascia detected by ultrasonographic examination. Risk factors for incisional hernias and the diagnostic validity of clinical symptoms and palpation during the Valsalva maneuver were determined. RESULTS: After a median follow-up of 35 months (range, 5-77 months), hernia prevalence was 32.4%. Among patients with a body mass index (calculated as weight in kilograms divided by height in meters squared) of less than 30, hernia prevalence was 25.8%; among patients with a body mass index of 30 or higher, hernia prevalence was 59.1%. Palpation demonstrated the highest sensitivity (58.3%). One in 6 patients had discomfort at the temporary stoma site and no palpable defect but showed an incisional hernia on ultrasonographic examination. Obesity was the sole significant risk factor identified in this study (odds ratio, 5.53; 95% confidence interval, 1.72-17.80). The presence of a stoma in situ for less than 6 months showed a trend toward being a risk factor (odds ratio, 2.38; 95% confidence interval, 0.96-5.99). CONCLUSION: Incisional hernias occur in 1 of 3 temporary stoma wounds, and a body mass index of 30 or higher is a risk factor.

Polypropylene meshes to prevent abdominal herniation. Can stable coatings prevent adhesions in the long term?

Abdominal surgery is associated with a significant risk for incisional herniation. Hernia repair is routinely performed by implantation of synthetic meshes. Such meshes may cause serious adhesions between the implanted material and organs leading to intestinal obstruction or enterocutaneous fistulas. This study compares three knitted meshes for their capacity to prevent adhesion formation in an in vivo study. The meshes evaluated are polypropylene (Prolene), polypropylene coated with oxygenated regenerated cellulose-in principle-a biodegradable biomaterial (Proceed, and Prolene coated with a nondegradable copolymer of the hydrophilic building block N-vinyl pyrrolidone (NVP) and the hydrophobic building block n-butylmethacrylate (BMA). The meshes were implanted in the abdomen of rats (follow-up 7 or 30 days). After 7 days, the formation of adhesions decreased in the order: Prolene > NVP/BMA-coated Prolene > Proceed; after 30 days, this order changed into: Proceed > Prolene > NVP/BMA-coated Prolene. Both at 7 and at 30 days, Proceed was the only mesh surrounded by macrophage cells that contained foreign materials, presumably degradation products of the (biodegradable) surface coating. The data indicate that long-term protection of implanted meshes against excessive adhesions may be achieved through stable biocompatible hydrogel surface coatings.