IMARI: multi-Interventional program for prevention and early Management of Anastomotic leakage after low anterior resection in Rectal cancer patIents: rationale and study protocol

Background

Anastomotic leakage (AL) is still a common and feared complication after low anterior resection (LAR) for rectal cancer. The multifactorial pathophysiology of AL and lack of standardised treatment options requires a multi-modal approach to improve long-term anastomotic integrity. The objective of the IMARI-trial is to determine whether the one-year anastomotic integrity rate in patients undergoing LAR for rectal cancer can be improved using a multi-interventional program.

Methods

IMARI is a multicentre prospective clinical effectiveness trial, whereby current local practice (control cohort) will be evaluated, and subsequently compared to results after implementation of the multi-interventional program (intervention cohort). Patients undergoing LAR for rectal cancer will be included. The multi-interventional program includes three preventive interventions (mechanical bowel preparation with oral antibiotics, tailored full splenic flexure mobilization and intraoperative fluorescence angiography using indocyanine green) combined with a standardised pathway for early detection and active management of AL. The primary outcome is anastomotic integrity, confirmed by CT-scan at one year postoperatively. Secondary outcomes include incidence of AL, protocol compliance and association with AL, temporary and permanent stoma rate, reintervention rate, quality of life and functional outcome. Microbiome analysis will be conducted to investigate the role of the rectal microbiome in AL.

In a Dutch nationwide study, the AL rate was 20%, with anastomotic integrity of 90% after one year. Based on an expected reduction of AL due to the preventive approaches of 50%, and increase of anastomotic integrity by a standardised pathway for early detection and active management of AL, we hypothesised that the anastomotic integrity rate will increase from 90 to 97% at one year. An improvement of 7% in anastomotic integrity at one year was considered clinically relevant. A total number of 488 patients (244 per cohort) are needed to detect this difference, with 80% statistical power.

Discussion

The IMARI-trial is designed to evaluate whether a multi-interventional program can improve long-term anastomotic integrity after rectal cancer surgery. The uniqueness of IMARI lies in the multi-modal design that addresses the multifactorial pathophysiology for prevention, and a standardised pathway for early detection and active treatment of AL.

Trial registration

Trialregister.nl (NL8261), January 2020.

New national recommendations for the treatment of pediatric differentiated thyroid carcinoma in the Netherlands

BACKGROUND

Currently, there are no European recommendations for the management of pediatric thyroid cancer. Other current international guidelines are not completely concordant. In addition, medical regulations differ between, for instance, the US and Europe. We aimed to develop new, easily accessible national recommendations for differentiated thyroid carcinoma (DTC) patients <18 years of age in the Netherlands as a first step toward a harmonized European Recommendation.

METHODS

A multidisciplinary working group was formed including pediatric and adult endocrinologists, a pediatric radiologist, a pathologist, endocrine surgeons, pediatric surgeons, pediatric oncologists, nuclear medicine physicians, a clinical geneticist and a patient representative. A systematic literature search was conducted for all existing guidelines and review articles for pediatric DTC from 2000 until February 2019. The Appraisal of Guidelines, Research and Evaluation (AGREE) instrument was used for assessing quality of the articles. All were compared to determine dis- and concordances. The American Thyroid Association (ATA) pediatric guideline 2015 was used as framework to develop specific Dutch recommendations. Discussion points based upon expert opinion and current treatment management of DTC in children in the Netherlands were identified and elaborated.

RESULTS

Based on the most recent evidence combined with expert opinion, a 2020 Dutch recommendation for pediatric DTC was written and published as an online interactive decision tree (www.oncoguide.nl).

CONCLUSION

Pediatric DTC requires a multidisciplinary approach. The 2020 Dutch Pediatric DTC Recommendation can be used as a starting point for the development of a collaborative European recommendation for treatment of pediatric DTC.

Diagnostic accuracy of serum alpha-fetoprotein levels in diagnosing recurrent sacrococcygeal teratoma: A systematic review

BACKGROUND

The incidence of children developing recurrent sacrococcygeal teratoma (SCT) is 2-35%. Serum alpha-fetoprotein (AFP) is often used as a tumor marker for (malignant) recurrences of SCT and could potentially be used during routine follow-up after SCT resection. However, the diagnostic accuracy of serum AFP levels during follow-up has not been well established. Therefore, we aimed to systematically review the diagnostic accuracy of serum AFP levels in recurrent SCT.

METHODS

We queried Search Premier, COCHRANE Library, EMCARE, EMBASE, PubMed, ScienceDirect and Web of Science databases to identify studies regarding patients with SCT with follow-up using serum AFP levels postoperative. We estimated sensitivity and specificity of serum AFP levels.

RESULTS

Fifteen studies (613 patients, 121 recurrences) were included and these mainly described serum AFP levels in patients with recurrent SCT (n = 111); 83 (75%) patients with recurrent SCT had elevated serum AFP levels. A subgroup analysis of articles that measured serum AFP levels in all patients (n = 6, 136 patients, 14 recurrences) showed a sensitivity and specificity of 79% and 95%, respectively. The sensitivity of AFP levels to detect malignant recurrence was 96%.

CONCLUSION

Diagnostic accuracy of serum AFP levels to detect recurrent SCT seems promising, though sensitivity could be overestimated since serum AFP levels are mainly described in patients with elevated AFP levels or at recurrent SCT. Furthermore, serum AFP levels could be helpful to detect malignant recurrences.

TYPE OF STUDY

Systematic review of level 2-4 studies.

LEVEL OF EVIDENCE

Level 2-4 (mostly level 2).

Perioperative apnea in infants with hypertrophic pyloric stenosis: A systematic review

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) leads to excessive vomiting and metabolic alkalosis, which may subsequently cause apnea. Although it is generally assumed that metabolic derangements should be corrected prior to surgery to prevent apnea, the exact incidence of perioperative apneas in infants with IHPS and the association with metabolic alkalosis are unknown. We performed this systematic review to assess the incidence of apnea in infants with IHPS and to verify the possible association between apnea and metabolic alkalosis.

METHODS

We searched MEDLINE, Embase, and Cochrane library to identify studies regarding infants with metabolic alkalosis, respiratory problems, and hypertrophic pyloric stenosis. We conducted a descriptive synthesis of the findings of the included studies.

RESULTS

Thirteen studies were included for analysis. Six studies described preoperative apnea, three studies described postoperative apnea, and four studies described both. All studies were of low quality or had other research questions. We found an incidence of 27% of preoperative and 0.2%-16% of postoperative apnea, respectively. None of the studies examined the association between apnea and metabolic alkalosis in infants with IHPS.

CONCLUSIONS

Infants with IHPS may have a risk to develop perioperative apnea. However, the incidence rates should be interpreted with caution because of the low quality and quantity of the studies. Therefore, further studies are required to determine the incidence of perioperative apnea in infants with IHPS. The precise underlying mechanism of apnea in these infants is still unknown, and the role of metabolic alkalosis should be further evaluated.

Diagnostic accuracy of urinary intestinal fatty acid binding protein in detecting colorectal anastomotic leakage

BACKGROUND

Anastomotic leakage (AL) remains a severe complication following colorectal surgery, having a negative impact on both short- and long-term outcomes. Since timely detection could enable early intervention, there is a need for the development of novel and accurate, preferably, non-invasive markers. The aim of this study was to investigate whether urinary intestinal fatty acid binding protein (I-FABP) could serve as such a marker.

METHODS

This prospective multicenter cross-sectional phase two diagnostic study was conducted at four centers in the Netherlands between March 2015 and November 2016. Urine samples of 15 patients with confirmed colorectal AL and 19 patients without colorectal AL on postoperative day 3 were included. Urinary I-FABP levels were determined using enzyme-linked immunosorbent assays and adjusted for urinary creatinine to compensate for renal dysfunction.

RESULTS

Urinary I-FABP levels were significantly elevated in patients with confirmed AL compared to patients without AL on postoperative day 3 (median: 2.570 ng/ml vs 0.809 ng/ml, p = 0.006). The area under the receiver operating characteristics curve (AUROC) was 0.775, yielding a sensitivity of 80% and specificity of 74% at the optimal cutoff point (> 1.589 ng/ml). This difference remained significant after calculation of I-FABP/creatinine ratios (median: 0.564 ng/µmol vs. 0.158 ng/µmol, p = 0.040), with an AUROC of 0.709, sensitivity of 60% and specificity of 90% at the optimal cutoff point (> 0.469 ng/µmol).

CONCLUSIONS

Levels of urinary I-FABP and urinary I-FABP/creatinine were significantly elevated in patients with confirmed AL following colorectal surgery, suggesting their potential as a non-invasive biomarker for colorectal anastomotic leakage.

Comparison of laparoscopic and open pyloromyotomy: Concerns for omental herniation at port sites after the laparoscopic approach

Pyloromyotomy is a common surgical procedure in infants with hypertrophic pyloric stenosis and can be performed with a small laparotomy or laparoscopically. No specific complications have been documented about one of the approaches. We aim to study (severity of) complications of pyloromyotomy and to compare complications of both approaches. Children undergoing pyloromyotomy between 2007 and 2017 were analyzed retrospectively. Complication severity was classified using the Clavien-Dindo classification. We included 474 infants (236 open; 238 laparoscopic). 401 were male (85%) and median (IQR) age was 33 (19) days. There were 83 surgical complications in 71 patients (15.0%). In the open group 45 infants (19.1%) experienced a complication vs. 26 infants in the laparoscopic group (10.5%)(p = 0.013). Severity and quantity of postoperative complications were comparable between both groups. Serosal tears of the stomach (N = 19) and fascial dehiscence (N = 8) occurred only after open pyloromyotomy. Herniation of omentum through a port site occurred only after laparoscopy (N = 6) and required re-intervention in all cases. In conclusion, the surgical complication rate of pyloromyotomy was 15.0%. Serosal tear of the stomach and fascial dehiscence are only present after open pyloromyotomy and omental herniation after laparoscopy respectively. The latter complication is underestimated and requires attention.

Human Fetal TNF-α-Cytokine-Producing CD4+ Effector Memory T Cells Promote Intestinal Development and Mediate Inflammation Early in Life

Although the fetal immune system is considered tolerogenic, preterm infants can suffer from severe intestinal inflammation, including necrotizing enterocolitis (NEC). Here, we demonstrate that human fetal intestines predominantly contain tumor necrosis factor-α (TNF-α)⁺CD4⁺CD69⁺ T effector memory (Tem) cells. Single-cell RNA sequencing of fetal intestinal CD4⁺ T cells showed a T helper 1 phenotype and expression of genes mediating epithelial growth and cell cycling. Organoid co-cultures revealed a dose-dependent, TNF-α-mediated effect of fetal intestinal CD4⁺ T cells on intestinal stem cell (ISC) development, in which low T cell numbers supported epithelial development, whereas high numbers abrogated ISC proliferation. CD4⁺ Tem cell frequencies were higher in inflamed intestines from preterm infants with NEC than in healthy infant intestines and showed enhanced TNF signaling. These findings reveal a distinct population of TNF-α-producing CD4⁺ T cells that promote mucosal development in fetal intestines but can also mediate inflammation upon preterm birth.

The incidence of associated abnormalities in patients with sacrococcygeal teratoma

BACKGROUND

Gross genetic causes for SCT are unknown; however, it might be associated with other abnormalities. We assessed the incidence of associated abnormalities in a large national cohort of neonates with SCT and aimed to identify predictive risk factors.

PROCEDURE

The medical records were reviewed of 235 consecutive neonates with SCT treated at the six pediatric surgical centers in the Netherlands from 1970 to 2010. Potential risk factors for associated abnormalities analyzed included sex, gestational age, tumor-volume/histology and Altman-classification.

RESULTS

In 76 patients (32.3%) at least one associated abnormality was diagnosed, with hydronephrosis as the most common (16.2%) and hip dysplasia in 4.3%. Multiple abnormalities were documented for 21 (9.0%). Prematurity and Altman type IV SCT were associated with an increased risk of any associated abnormality. No association between increased tumor-volume and hydronephrosis or hip dysplasia was found. Patients with type IV Altman SCT had a fourfold risk of suffering from hydronephrosis compared to Altman type I SCT.

CONCLUSIONS

SCT was associated with other abnormalities in one-third of children. Some were tumor-related while others were related to prematurity or occurred sporadically. In contrast to clinically obvious anomalies, hip dysplasia or hydronephrosis might be latently present with more subtle clinical presentation. We therefore suggest renal- and hip-ultrasound in all patients, certainly those with Altman type IV SCT.

LEVEL OF EVIDENCE RATING

Level II (retrospective study).

Diagnostic accuracy of preoperative ultrasonography in predicting contralateral inguinal hernia in children: a systematic review and meta-analysis

Objectives

The incidence of children developing metachronous contralateral inguinal hernia (MCIH) is 7–15%. Contralateral groin exploration during unilateral hernia repair can prevent MCIH development and subsequent second surgery and anaesthesia. Preoperative ultrasonography is a less invasive strategy and potentially able to detect contralateral patent processus vaginalis (CPPV) prior to MCIH development.

Methods

We queried MEDLINE, Embase and Cochrane library to identify studies regarding children aged < 18 years diagnosed with unilateral inguinal hernia without clinical signs of contralateral hernia, who underwent preoperative ultrasonography of the contralateral groin. We assessed heterogeneity and used a random-effects model to obtain pooled estimates of sensitivity, specificity and area under the receiver operating characteristic curve (AUC).

Results

Fourteen studies (2120 patients) were included, seven (1013 patients) in the meta-analysis. In studies using surgical exploration as reference test (n = 4, 494 patients), pooled sensitivity and specificity were 93% and 88% respectively. In studies using contralateral exploration as reference test following positive and clinical follow-up after negative ultrasonographic test results (n = 3, 519 patients), pooled sensitivity was 86% and specificity 98%. The AUC (0.984) shows high diagnostic accuracy of preoperative ultrasonography for detecting CPPV, although diagnostic ultrasonographic criteria largely differ and large heterogeneity exists. Reported inguinal canal diameters in children with CPPV were 2.70 ± 1.17 mm, 6.8 ± 1.3 mm and 9.0 ± 1.9 mm.

Conclusion

Diagnostic accuracy of preoperative ultrasonography to detect CPPV seems promising, though may result in an overestimation of MCIH prevalence, since CPPV does not invariably lead to MCIH. Unequivocal ultrasonographic criteria are mandatory for proper diagnosis of CPPV and subsequent prediction of MCIH.

Key Points

• Diagnostic accuracy of preoperative ultrasonography for detection of CPPV in children with unilateral inguinal hernia is high.

• Preoperative ultrasonographic evaluation of the contralateral groin assumedly results in an overestimation of MCIH prevalence.

• Unequivocal ultrasonographic criteria are mandatory for proper diagnosis of CPPV and risk factor identification is needed to predict whether CPPV develops into clinically apparent MCIH.

Electronic supplementary material

The online version of this article (10.1007/s00330-018-5625-6) contains supplementary material, which is available to authorized users.

Functional mucous layer and healing of proximal colonic anastomoses in an experimental model

BACKGROUND

Anastomotic leakage (AL) is the most dreaded complication after colorectal surgery, causing high morbidity and mortality. Mucus is a first line of defence against external factors in the gastrointestinal tract. In this study, the structural mucus protein Muc2 was depleted in genetically engineered mice and the effect on healing of colonic anastomoses studied in an experimental model.

METHODS

Mice of different Muc2 genotypes were used in a proximal colonic AL model. Tissues were scored histologically for inflammation, bacterial translocation was determined by quantitative PCR of bacterial 16S ribosomal DNA, and epithelial cell damage was determined by assessing serum levels of intestinal fatty acid-binding protein.

RESULTS

Of 22 Muc2-deficient (Muc2^-/- ) mice, 20 developed AL, compared with seven of 22 control animals (P < 0·001). Control mice showed normal healing, whereas Muc2^-/- mice had more inflammation with less collagen deposition and neoangiogenesis. A tendency towards higher bacterial translocation was seen in mesenteric lymph nodes and spleen in Muc2^-/- mice. Intestinal fatty acid-binding protein levels were significantly higher in Muc2^-/- mice compared with controls (P = 0·011).

CONCLUSION

A functional mucous layer facilitates the healing of colonic anastomoses. Clinical relevance Colorectal anastomotic leakage remains the most dreaded complication after colorectal surgery. It is known that the aetiology of anastomotic leakage is multifactorial, and a role is suggested for the interaction between intraluminal content and mucosa. In this murine model of proximal colonic anastomotic leakage, the authors investigated the mucous layer at the intestinal mucosa, as the first line of defence, and found that a normal, functioning mucous layer is essential in the healing process of colonic anastomoses. Further research on anastomotic healing should focus on positively influencing the mucous layer to promote better postoperative recovery.

Serological markers for human intestinal ischemia: A systematic review

Early and accurate diagnosis of intestinal ischemia is important in order to provide rapid and correct treatment and reduce morbidity and mortality rates. Clinical signs and symptoms are often unspecific. This systemic review sums up literature regarding human plasma biomarkers for acute mesenteric ischemia reported during the last ten years. Classic, general markers, including lactate, white cell count, base excess, show poor diagnostic accuracy for intestinal ischemia. Preliminary results for ischemia-modified albumin are promising, which is also true for the inflammatory marker procalcitonin. Best diagnostic accuracy is described for D-dimer, a-Glutathione S-transferase (a-GST) and Intestinal fatty acid binding protein (I-FABP), reflecting coagulation activity and mucosal damage respectively. Future studies should be directed at phase four questions (Do patients who undergo the diagnostic test fare better (in their ultimate health outcomes) than similar patients who do not?) for these markers and the identification of additional, novel plasma biomarkers signaling various types and stages of intestinal ischemia.

Hemorrhage is the most common cause of neonatal mortality in patients with sacrococcygeal teratoma

BACKGROUND

A small percentage of neonates with sacrococcygeal teratoma die shortly after birth from hemorrhagic complications. The incidence of and risk factors associated with hemorrhagic mortality are unknown. In this multicenter study we determined the incidence of early death in neonates born with SCT and evaluated potential risk factors for hemorrhagic mortality.

METHODS

235 children with SCT treated from 1970 to 2010 in the Netherlands were retrospectively included. The following candidate risk factors for hemorrhagic mortality were examined: sex, prematurity, Altman type, tumor volume, tumor histology, necessity of emergency operation and time of diagnosis.

RESULTS

Eighteen patients (7.7%) died at a median age of 163.5days (range 1.7-973days). Nine patients died of a malignancy. Nine others (3.8%) died postnatally (age 1-27days), six even within two days after birth. In seven of these nine patients death was related to tumor-hemorrhage and/or circulatory failure. Risk factors for hemorrhagic mortality were prematurity, tumor volume>1000cm³ and performance of an emergency operation.

CONCLUSIONS

Hemorrhagic mortality of neonates with SCT is relatively high (3.8%) representing almost 70% of the overall mortality in the neonatal period. High-output cardiac failure, internal tumor hemorrhage and perioperative bleeding were the most common causes of early death and were all strongly associated with larger tumor sizes.

LEVEL-OF-EVIDENCE RATING

II (Retrospective study).

Sexual function after treatment for sacrococcygeal teratoma during childhood

BACKGROUND

Children treated for sacrococcygeal teratoma (SCT) may suffer from sexual dysfunction later in life because of the extended pelvic surgery performed, however, structured evaluations have not been performed yet.

METHODS

The Female Sexual Function Index (FSFI), the International Index of Erectile Function (IIEF) and the Body Image Questionnaire (BIQ) were sent to patients (≥18years) treated for SCT in the Dutch pediatric surgical centers after 1970.

RESULTS

Forty-five of 76 patients returned the questionnaires; 28 women (median age 27.3years, range 18.3-41.0) and seven men (median age 22.0years, range 19.1-36.5) were eligible for analysis. The FSFI and IIEF results were compared to healthy controls. Female patients scored significantly lower on the desire (p=0.014), arousal (p=0.013) and lubrication domain (p=0.019). FSFI total-scores of female patients were significantly lower compared to controls [median 30.5 (IQR 28.6-31.4) vs. median 32.4 (IQR 30.6-33.45) p≤0.001] but were above the threshold value for sexual dysfunction. Males reported normal erectile function and penetration ability with normal ejaculation. Females had significant lower BIQ results compared to males; BIQ-cosmesis scores were moderately correlated to the FSFI-desire score (r=-0.37, p=0.028).

CONCLUSION

SCT resection in girls may result in diminished sexual function at adult age with worse self-perceived body image. The possibility of sexual complaints should be integrated in the surveillance strategies for these patients.

Patient-Reported Defecation and Micturition Problems Among Adults Treated for Sacrococcygeal Teratoma During Childhood--The Need for New Surveillance Strategies

BACKGROUND

To evaluate defecation and micturition complaints in adults treated for sacrococcygeal teratoma (SCT) during childhood and to identify risk factors for soiling, urinary incontinence, and constipation beyond childhood.

PROCEDURE

Records of patients aged ≥18 treated for SCT during infancy in the Netherlands were retrospectively reviewed. Frequency and severity of soiling, constipation, and urinary incontinence were evaluated using questionnaires designed in line with the Krickenbeck classification. Problems during childhood were compared to outcomes at adult age in part of the cohort. Associations between patient- and disease-related factors with complaints beyond childhood were analyzed with the chi-square test or Fisher's exact test, when appropriate.

RESULTS

Of 47 included patients (mean age 26.2 years, SD ±6.5), 49% reported at least one defecation or micturition complaint. Urinary incontinence was present in 30% and had a greater negative impact than soiling (24%). Ten patients (21%) reported constipation; five found this severely bothering. Three patients reported social restrictions due to defecation or micturition complaints (6.4%). While sex and tumor histology were not identified as risk factors, a tumor diameter of >10 cm and Altman type I or type II SCT were associated with constipation during adulthood.

CONCLUSIONS

One-third of the patients treated for SCT during childhood reported urinary and defecation problems beyond childhood. In only a minority of cases, these led to social restrictions. A greater tumor diameter was associated with a higher risk of constipation during adulthood. Prolonged surveillance strategies are advised for all patients with SCT.

Life and death at the mucosal-luminal interface: New perspectives on human intestinal ischemia-reperfusion

Intestinal ischemia is a frequently observed phenomenon. Morbidity and mortality rates are extraordinarily high and did not improve over the past decades. This is in part attributable to limited knowledge on the pathophysiology of intestinal ischemia-reperfusion (IR) in man, the paucity in preventive and/or therapeutic options and the lack of early diagnostic markers for intestinal ischemia. To improve our knowledge and solve clinically important questions regarding intestinal IR, we developed a human experimental intestinal IR model. With this model, we were able to gain insight into the mechanisms that allow the human gut to withstand short periods of IR without the development of severe inflammatory responses. The purpose of this review is to overview the most relevant recent advances in our understanding of the pathophysiology of human intestinal IR, as well as the (potential) future clinical implications.

Evaluation of chemotherapeutic sequelae and quality of life in survivors of malignant sacrococcygeal teratoma

PURPOSE

The impact of chemotherapeutic sequelae on long-term quality of life (QoL) for survivors of malignant sacrococcygeal teratoma (SCT) is unknown. The incidence of chemotherapeutic toxicity in patients treated for malignant SCT and possible effects on the QoL were analyzed.

METHODS

Retrospective chart review of patients ≥18 years treated for SCT in the Netherlands was performed. Present QoL was evaluated using the SF-36 questionnaire. The results of survivors of malignant SCT were compared to those of patients treated for benign SCT.

RESULTS

Fifty-one of 76 traceable patients consented to participate. The results of 47 (92.2 %), 9 men and 38 women (median age 25.4 years, range 18.3-41.2), were analyzed. Eleven had been treated for malignancy; 63.6 % suffered from at least one chemotherapeutic sequel with hearing loss as the most common one. Results for both groups were similar on all but one SF-36 subcategory; those treated for malignant tumor scored significantly lower on the subcategory physical functioning (p = 0.02).

CONCLUSION

Despite the high incidence of chemotherapeutic sequelae among survivors of malignant SCT, their QoL does not differ from that of those treated for benign SCT. Even though their physical functioning is restricted, daily activities and psychosocial functioning of survivors of malignant SCT are not restricted.

International consensus statement regarding the use of animal models for research on anastomoses in the lower gastrointestinal tract

PURPOSE

This project aimed to reach consensus on the most appropriate animal models and outcome measures in research on anastomoses in the lower gastrointestinal tract (GIT). The physiology of anastomotic healing remains an important research topic in gastrointestinal surgery. Recent results from experimental studies are limited with regard to comparability and clinical translation.

METHODS

PubMed and EMBASE were searched for experimental studies investigating anastomotic healing in the lower GIT published between January 1, 2000 and December 31, 2014 to assess currently used models. All corresponding authors were invited for a Delphi-based analysis that consisted of two online survey rounds followed by a final online recommendation survey to reach consensus on the discussed topics.

RESULTS

Two hundred seventy-seven original articles were retrieved and 167 articles were included in the systematic review. Mice, rats, rabbits, pigs, and dogs are currently being used as animal models, with a large variety in surgical techniques and outcome measures. Forty-four corresponding authors participated in the Delphi analysis. In the first two rounds, 39/44 and 35/39 participants completed the survey. In the final meeting, 35 experts reached consensus on 76/122 items in six categories. Mouse, rat, and pig are considered appropriate animal models; rabbit and dog should be abandoned in research regarding bowel anastomoses. ARRIVE guidelines should be followed more strictly.

CONCLUSIONS

Consensus was reached on several recommendations for the use of animal models and outcome measurements in research on anastomoses of the lower GIT. Future research should take these suggestions into account to facilitate comparison and clinical translation of results.

Colorectal anastomotic healing: why the biological processes that lead to anastomotic leakage should be revealed prior to conducting intervention studies

BACKGROUND

Anastomotic leakage (AL) remains the most dreaded complication after colorectal surgery and causes high morbidity and mortality. The pathophysiology of AL remains unclear, despite numerous studies that have been conducted on animals and humans, probably due to the undetermined healing process of colorectal anastomoses. Increasing basic knowledge on this healing process may shed more light on causal factors of AL, and additionally reduce the quantity and accelerate the quality of experimental studies. In this debate article, our aim was to provide different perspectives on what is known about the colorectal healing process in relation to wound healing and AL.

DISCUSSION

Since knowledge on anastomotic healing is lacking, it remains difficult to conclude which factors are essential in preventing AL. This is essential information in the framework of humane animal research, where the focus should lie on Replacement, Reduction and Refinement (3Rs). While many researchers compare anastomotic healing with wound healing in the skin, there are substantial recognized differences, e.g. other collagen subtypes and different components involved. Based on our findings in literature as well as discussions with experts, we advocate stop considering anastomotic healing in the gastrointestinal tract and cutaneous healing as a similar process. Furthermore, intervention studies should at least address the anastomotic healing process in terms of histology and certain surrogate markers. Finally, the anastomotic healing process ought to be further elucidated - with modern techniques to achieve 3Rs in animal research--to provide starting points for potential interventions that can prevent AL.

Sarcopenia is highly prevalent in patients undergoing surgery for gastric cancer but not associated with worse outcomes

OBJECTIVES

Aim of this study was to assess the prevalence of sarcopenia and body composition (i.e., subcutaneous and visceral fat) in gastric cancer surgical patients and its association with adverse postoperative outcome.

METHODS

Preoperative CT scans were obtained from all patients who underwent surgery for gastric adenocarcinoma between January 2005 and September 2012. Total muscle and adipose tissue cross-sectional area were measured at the level of the third lumbar vertebra (L3) transverse processes. Sarcopenia was defined according to gender- and body mass index (BMI)-specific cutoff points. Primary outcome was in-hospital mortality. Secondary outcomes were severe postoperative complications (i.e., Clavien-Dindo classification ≥3a complications) and 6-month mortality.

RESULTS

In 152 out of a total of 180 (84.4%) patients, a CT-scan was available for analysis. In total, 86 (57.7%) of the patients were classified as sarcopenic. Sarcopenia was no predictor for in-hospital mortality (P = 0.52), severe complications (P = 1.00) or 6-month mortality (P = 0.69). Intraabdominal and subcutaneous adipose tissue measurements were not associated with in-hospital mortality, severe complications or 6-month mortality.

CONCLUSIONS

In this population of gastric cancer surgical patients, the prevalence of sarcopenia was 57.7%, which is high compared to other abdominal surgical oncology populations. However, sarcopenia was not associated with postoperative morbidity or mortality.

Loss of Skeletal Muscle Mass During Neoadjuvant Chemoradiotherapy Predicts Postoperative Mortality in Esophageal Cancer Surgery

Background

Esophageal surgery is associated with complications and mortality. It is highly important to develop tools predicting unfavorable postoperative outcome. Esophageal cancer and neoadjuvant chemoradiotherapy (CRT) induce skeletal muscle wasting, which leads to diminished physiologic reserves. The purpose of this study was to investigate whether the degree of muscle mass lost during neoadjuvant CRT predicts postoperative mortality.

Methods

A total of 123 consecutive patients undergoing surgery for esophageal malignancy in the period 2008–2012 were included, of whom 114 received neoadjuvant CRT. Skeletal muscle mass was measured on routinely performed CT scans by assessing L3 muscle index (according to the Prado method) before and after neoadjuvant CRT, and the amount of muscle mass lost during neoadjuvant CRT (muscle loss index) was calculated. It was investigated whether this amount was associated with postoperative 30-day or in-hospital mortality and morbidity.

Results

In the complete cohort, no significant association between loss of muscle mass and mortality was found. However, skeletal muscle mass was significantly lower in patients with stage III–IV tumors compared with stage I–II tumors, prior to neoadjuvant CRT. In the stage III–IV subgroup, the amount of muscle mass lost during neoadjuvant CRT was predictive of postoperative mortality: −13.5 % (standard deviation 6.2 %) in patients who died postoperatively compared with −5.0 % (standard deviation 8.3 %) in surviving patients, p = 0.02.

Conclusions

Measurement of muscle mass loss during neoadjuvant chemoradiotherapy may provide a readily available and inexpensive assessment to identify patients at risk for developing unfavorable postoperative outcome after resection of esophageal malignancies, especially in patients with stage III–IV tumors.

Temporary gastric banding in a premature infant with esophageal atresia and severe respiratory distress syndrome

The management of premature, very low birth weight infants with esophageal atresia and tracheo-esophageal fistula complicated by respiratory insufficiency is still challenging. We present a case of a premature, very low weight infant in whom we used a technique of temporary gastric banding to control the air leak through the fistula.

Nasal carriage of Staphylococcus aureus among surgeons and surgical residents: a nationwide prevalence study

BACKGROUND

Staphylococcus aureus nasal carriage is an independent risk factor for developing nosocomial infections and for developing surgical site infection (SSI) in particular. The number of post-operative nosocomial S. aureus infections can be reduced by screening patients and decolonizing nasal carriers. In addition to patients, health care workers may also be S. aureus nasal carriers. The aim of this study was to explore S. aureus nasal carriage rates among surgeons.

METHODS

Nasal swabs were collected from surgeons and surgical residents during a national surgical congress. The control group consisted of non-hospitalized patients. Staphylococcus aureus carriage was detected using selective chromogenic agars by use of a fully automated inoculator. Suspected colonies were identified further by positive catalase and slide coagulation reactions.

RESULTS

Samples were collected from 366 surgeons and surgical residents and 950 control patients. The S. aureus nasal carriage rate among surgeons and residents was significantly greater compared with the control group (45.4% versus 30.8%, odds ratio [OR] 1.86 [1.45-2.38], p<0.001). No significant difference in carriage rate was found between surgeons and residents (46.8% versus 43.3%, p=0.769) and years of experience as a surgeon was not associated with a greater carriage rate. Male gender was an independent risk factor for carriage among physicians odds ratio ([OR] 1.90 [95% confidence interval 1.19-3.01], p=0.007).

CONCLUSIONS

The nationwide rate of S. aureus nasal carriage among surgeons and surgical residents proved to be significantly greater compared with a non-hospitalized patient control group. Male gender is an independent risk factor for carriage among physicians. Future studies are needed to investigate the possible relation with nosocomial post-operative S. aureus infections.

Malignant transformation in sacrococcygeal teratoma and in presacral teratoma associated with Currarino syndrome: a comparative study

BACKGROUND/PURPOSE

The risk of malignant transformation of sacrococcygeal teratoma (SCT) and of presacral teratoma in Currarino syndrome (CS) may differ despite the similar position and appearance.

METHODS

Malignant transformation and teratoma recurrence were assessed in a national retrospective comparative analysis of 205 SCT and 16 CS patients treated in one of the six pediatric surgical centers in the Netherlands between January 1981 and December 2010.

RESULTS

The malignancy free survival of patients with SCT was lower than for patients with a presacral teratoma associated with CS (80% and 58% after one and two years in SCT versus 100% after two years in CS, p=0.017) CONCLUSIONS: In SCT, malignancy and recurrence risk are high. Therefore, early and complete resection is mandatory. Our data show that the risk of malignant transformation of a presacral teratoma in CS is small.

Evaluation of pregnancy and delivery in 13 women who underwent resection of a sacrococcygeal teratoma during early childhood

BACKGROUND

Sacrococcygeal teratoma resection often brings changes in pelvic anatomy and physiology with possible consequences for defecation, micturition and sexual function. It is unknown, whether these changes have any gynecological and obstetric sequelae. Until now four pregnancies after sacrococcygeal teratoma resection have been described and cesarean section has been suggested to be the method of choice for delivery. We evaluated the pregnancy course and mode of delivery in women previously treated for a sacrococcygeal teratoma.

METHODS

The records of all patients who underwent sacrococcygeal teratoma resection after 1970 in one of the six pediatric surgical centers in the Netherlands were reviewed retrospectively. Women aged 18 years and older were eligible for participation. Patient characteristics, details about the performed operation and tumor histology were retrieved from the records. Consenting participants completed a questionnaire addressing fertility, pregnancy and delivery details.

RESULTS

Eighty-nine women were eligible for participation; 20 could not be traced. Informed consent was received from 41, of whom 38 returned the completed questionnaire (92.7%). Thirteen of these 38 women conceived, all but one spontaneously. In total 20 infants were born, 17 by vaginal delivery and 3 by cesarean section, in one necessitated by previous intra-abdominal surgery as a consequence of sacrococcygeal teratoma resection. Conversion to a cesarean section was never necessary. None of the 25 women without offspring reported involuntary childlessness.

CONCLUSIONS

There are no indications that resection of a sacrococcygeal teratoma in female patients is associated with reduced fertility: spontaneous pregnancy is possible and vaginal delivery is safe for mother and child, irrespective of the sacrococcygeal teratoma classification or tumor histology.

Intestinal fatty acid-binding protein: a possible marker for gut maturation

BACKGROUND

Gut immaturity is linked with postnatal intestinal disorders. However, biomarkers to assess the intestinal developmental stage around birth are lacking. The aim of this study was to gain more insight on intestinal fatty acid-binding protein (I-FABP) as an indicator of gut maturity.

METHODS

Antenatal I-FABP distribution and release was investigated in extremely premature, moderately premature, and term lambs, and these findings were verified in human urinary samples. Ileal I-FABP distribution was confirmed in autopsy material within 24 h postnatally.

RESULTS

Median (range) serum I-FABP levels were lower in extremely premature lambs compared with moderately premature lambs (156 (50.0-427) vs. 385 (100-1,387) pg/ml; P = 0.02). Contrarily, median early postnatal urine I-FABP levels in human infants were higher in extremely premature compared with moderately premature and term neonates (1,219 (203-15,044) vs. 256 (50-1,453) and 328 (96-1,749) pg/ml; P = 0.008 and P = 0.04, respectively). I-FABP expression was most prominent in nonvacuolated enterocytes and increased with rising gestational age (GA) in ovine and human tissue samples. The epithelial distribution pattern changed from a phenotype displaying I-FABP-positive enterocytes merely in the crypts early in gestation into a phenotype with I-FABP expressing cells exclusively present in the villus tips at term in ovine and human tissue.

CONCLUSION

In this ovine and human study, increasing GA is accompanied by an increase in I-FABP tissue content. Cord I-FABP levels correlate with gestation in ovine fetuses, identifying I-FABP as a marker for gut maturation. Raised postnatal urine I-FABP levels in preterm human infants may indicate intestinal injury and/or inflammation in utero.

Accurate prediction of anastomotic leakage after colorectal surgery using plasma markers for intestinal damage and inflammation

BACKGROUND

Anastomotic leakage is a frequent and life-threatening complication after colorectal surgery. Early recognition of anastomotic leakage is critical to reduce mortality. Because early clinical and radiologic signs of anastomotic leakage are often nonspecific, there is an urgent need for accurate biomarkers. Markers of inflammation and gut damage might be suitable, as these are hallmarks of anastomotic leakage.

STUDY DESIGN

In 84 patients undergoing scheduled colorectal surgery with primary anastomosis, plasma samples were collected preoperatively and daily after surgery. Inflammatory markers, C-reactive protein; calprotectin; and interleukin-6, and intestinal damage markers, intestinal fatty acid binding protein; liver fatty acid binding protein; and ileal bile acid binding protein, were measured. Diagnostic accuracy of single markers or combinations of markers was analyzed by receiver operating characteristic curve analysis.

RESULTS

Anastomotic leakage developed in 8 patients, clinically diagnosed at median day 6. Calprotectin had best diagnostic accuracy to detect anastomotic leakage postoperatively. Highest diagnostic accuracy was obtained when C-reactive protein and calprotectin were combined at postoperative day 3, yielding sensitivity of 100%, specificity of 89%, positive likelihood ratio = 9.09 (95% CI, 4.34-16), and negative likelihood ratio = 0.00 (95% CI, 0.00-0.89) (p < 0.001). Interestingly, preoperative intestinal fatty acid binding protein levels predicted anastomotic leakage at a cutoff level of 882 pg/mL with sensitivity of 50%, specificity of 100%, positive likelihood ratio = infinite (95% CI, 4.01-infinite), and negative likelihood ratio = 0.50 (95% CI, 0.26-0.98) (p < 0.0001).

CONCLUSIONS

Preoperative intestinal fatty acid binding protein measurement can be used for anastomotic leakage risk assessment. In addition, the combination of C-reactive protein and calprotectin has high diagnostic accuracy. Implementation of these markers in daily practice deserves additional investigation.

Non-invasive serum amyloid A (SAA) measurement and plasma platelets for accurate prediction of surgical intervention in severe necrotizing enterocolitis (NEC)

Objective

To evaluate the value of biomarkers to detect severe NEC.

Summary Background Data

The time point of surgery in necrotizing enterocolitis (NEC) is critical. Therefore, there is a need for markers that detect severe NEC, because clinical signs of severe NEC often develop late. This study evaluated the value of biomarkers reflecting intestinal cell damage and inflammation to detect severe NEC.

Methods

29 neonates with NEC were included. Two definitions of moderate versus severe NEC were analyzed: medical NEC (n = 12) versus surgical or fatal NEC (n = 17); and Bell stage II NEC (n = 13) versus stage III NEC (n = 16). Urinary intestinal fatty acid binding protein (I-FABP), serum amyloid A (SAA), C3a and C5a, and fecal calprotectin were measured. C-reactive protein (CRP), white blood cell count (WBC) and platelet count data were measured in blood.

Results

In both definitions of moderate versus severe NEC, urinary SAA levels were significantly higher in severe NEC. A cut-off value of 34.4 ng/ml was found in surgical NEC versus medical NEC (sensitivity, 83%; specificity, 83%; LR+, 4.88 (95% CI, 1.37–17.0); LR−, 0.20 (95% CI, 0.07–0.60)) at diagnosis of NEC and at one day prior to surgery in neonates who were operated later on. Combination of urinary SAA and platelet count increased the accuracy, with a sensitivity, 94%; specificity, 83%; LR+, 5.53 (95% CI, 1.57–20.0); and LR−, 0.07 (95% CI, 0.01–0.48).

Conclusion

Urinary SAA is an accurate marker in differentiating severe NEC from moderate NEC; particularly if combined with serum platelet count.

Evaluation of the diagnostic accuracy of plasma markers for early diagnosis in patients suspected for acute appendicitis

OBJECTIVES

The main objective of this study was to evaluate the diagnostic accuracy of two novel biomarkers, calprotectin (CP) and serum amyloid A (SAA), along with the more traditional inflammatory markers C-reactive protein (CRP) and white blood cell count (WBC), in patients suspected of having acute appendicitis (AA). The secondary objective was to compare diagnostic accuracy of these biomarkers with a clinical scoring system and radiologic imaging.

METHODS

A total of 233 patients with suspected AA, presenting to the emergency department (ED) between January 2010 and September 2010, and 52 healthy individuals serving as controls, were included in the study. Blood was drawn and CP and SAA-1 concentrations were measured using enzyme-linked immunosorbent assay (ELISA). CRP and WBC concentrations were routinely measured and retrospectively abstracted from the electronic health record, together with physical examination findings and radiologic reports. The Alvarado score was calculated as a clinical scoring system for AA. Final diagnosis of AA was based on histopathologic examination. The Mann-Whitney U-test was used for between-group comparisons. Receiver operating characteristic (ROC) curves were used to measure the diagnostic accuracy for the tests and to determine the best cutoff points.

RESULTS

Seventy-seven of 233 patients (33%) had proven AA. Median plasma levels for CP and SAA-1 were significantly higher in patients with AA than in those with another final diagnosis (CP, 320.9 ng/mL vs. 212.9 ng/mL; SAA-1, 30 mg/mL vs. 0.6 mg/mL; p < 0.001). CRP and WBC were significantly higher in patients with AA as well. The Alvarado score was helpful at the extremes (<3 or >7). Ultrasound (US) had a sensitivity of 84% and a specificity of 94%. Computed tomography (CT) had a sensitivity of 100% and a specificity of 91%. The area under the ROC (95% confidence interval [CI]) was 0.67 (95% CI = 0.60 to 0.74) for CP, 0.76 (95% CI = 0.70 to 0.82) for SAA, 0.71 (95% CI = 0.64 to 0.78) for CRP, and 0.79 (95% CI = 0.73 to 0.85) for WBC. No cutoff points had high enough sensitivity and specificity to accurately diagnose AA. However, a high sensitivity of 97% was shown at 7.5 × 10(9) /L for WBC and 0.375 mg/mL for SAA.

CONCLUSIONS

CP, SAA-1, CRP, and WBC were significantly elevated in patients with AA. None had cutoff points that could accurately discriminate between AA and other pathology in patients with suspected AA. A WBC < 7.5 × 10(9) /L, with a low level of clinical suspicion for AA, can identify a subgroup of patients who may be sent home without further evaluation, but who should have available next-day follow-up.

[The electronic health record: computerised provider order entry and the electronic instruction document as new functionalities]

An electronic health record (EHR) should provide 4 key functionalities: (a) documenting patient data; (b) facilitating computerised provider order entry; (c) displaying the results of diagnostic research; and (d) providing support for healthcare providers in the clinical decision-making process.- Computerised provider order entry into the EHR enables the electronic receipt and transfer of orders to ancillary departments, which can take the place of handwritten orders.- By classifying the computer provider order entries according to disorders, digital care pathways can be created. Such care pathways could result in faster and improved diagnostics.- Communicating by means of an electronic instruction document that is linked to a computerised provider order entry facilitates the provision of healthcare in a safer, more efficient and auditable manner.- The implementation of a full-scale EHR has been delayed as a result of economic, technical and legal barriers, as well as some resistance by physicians.

Noninvasive measurement of fecal calprotectin and serum amyloid A combined with intestinal fatty acid-binding protein in necrotizing enterocolitis

BACKGROUND

Diagnosis of necrotizing enterocolitis (NEC), prevalent in premature infants, remains challenging. Enterocyte damage in NEC can be assessed by intestinal fatty acid-binding protein (I-FABP), with a sensitivity of 93% and a specificity of 90%. Numerous markers of inflammation are known, such as serum amyloid A (SAA) and fecal calprotectin.

PURPOSE

The aim of the present study was to evaluate which combination of noninvasive measurement of inflammatory markers and I-FABP improves the diagnostic accuracy in neonates suspected for NEC.

METHODS

In 62 neonates with clinical suspicion of NEC (29 with final diagnosis of NEC), urinary I-FABP, urinary SAA, and fecal calprotectin levels were determined quantitatively. Diagnostic accuracy was calculated for the combinations I-FABP-SAA and I-FABP-fecal calprotectin, using a multivariable logistic regression model.

RESULTS

The combination of SAA and I-FABP did not increase the diagnostic accuracy of I-FABP. However, the combination of fecal calprotectin and I-FABP improved accuracy significantly. The combination of urinary I-FABP and fecal calprotectin measurement produced a sensitivity of 94%, a specificity of 79%, a positive likelihood ratio of 4.48, and a negative likelihood ratio of 0.08.

CONCLUSION

The combination of noninvasive measurement of I-FABP and fecal calprotectin seems promising for diagnosing NEC at an early time point. Prospective analysis is required to confirm this finding and to evaluate better treatment strategies based on noninvasive measurement of I-FABP and calprotectin.

Rapid lamina propria retraction and zipper-like constriction of the epithelium preserves the epithelial lining in human small intestine exposed to ischaemia-reperfusion

To ensure a sufficient barrier between a host and noxious luminal content, the intestinal epithelium must be equipped with efficient mechanisms to limit damage to the epithelial lining. Using a human model, we were able to investigate these mechanisms in the human gut exposed to ischaemia-reperfusion (IR) over the time course of 150 min. In 10 patients a part of jejunum, to be removed for surgical reasons, was selectively exposed to IR. Control tissue was collected, as well as tissue exposed to 30 min of ischaemia with 0, 30 or 120 min of reperfusion. Haematoxylin/eosin staining demonstrated the appearance of subepithelial spaces following 30 min of ischaemia, while the epithelial lining remained intact at this stage. Western blot for myosin light chain kinase (MLCK) revealed a significant increase in protein levels after ischaemia (p < 0.01), and selective staining of MLCK and phosphorylated MLC (pMLC) in lamina propria muscle fibres indicated that appearance of subepithelial spaces was a consequence of active villus contraction. Early during reperfusion, accumulation of pMLC was observed exclusively at the basal side of enterocytes that had lost contact with the collagen-IV-positive basement membrane. These epithelial sheets were pulled together like a zipper, even before these cells were shed. This constriction, verified by increased F-actin and pMLC double staining, accounted for a 45% reduction in virtual wound surface (p < 0.001) at 30 min of reperfusion. In addition, these mechanisms were involved in resealing remaining small epithelial defects, resulting in a fully restored epithelial lining within 120 min of reperfusion. In conclusion, we show in a human in vivo model that the human jejunum has the ability to preserve the epithelial lining during intestinal IR by rapid lamina propria contraction and zipper-like constriction of epithelial cells that are to be shed into the lumen. These newly described phenomena limit exposure to noxious luminal content.

Non-invasive markers of gut wall integrity in health and disease

The intestinal mucosa is responsible for the absorption of nutrients from the lumen and for the separation of the potentially toxic luminal content (external environment) from the host (internal environment). Disruption of this delicate balance at the mucosal interface is the basis for numerous (intestinal) diseases. Experimental animal studies have shown that gut wall integrity loss is involved in the development of various inflammatory syndromes, including post-operative or post-traumatic systemic inflammatory response syndrome, sepsis, and multiple organ failure. Assessment of gut wall integrity in clinical practice is still a challenge, as it is difficult to evaluate the condition of the gut non-invasively with currently available diagnostic tools. Moreover, non-invasive, rapid diagnostic means to assess intestinal condition are needed to evaluate the effects of treatment of intestinal disorders. This review provides a survey of non-invasive tests and newly identified markers that can be used to assess gut wall integrity.

Level of activation of the unfolded protein response correlates with Paneth cell apoptosis in human small intestine exposed to ischemia/reperfusion

BACKGROUND & AIMS

In the intestine, Paneth cells participate in the innate immune response. Their highly secretory function makes them susceptible to environmental conditions that cause endoplasmic reticulum (ER) stress. We investigated whether intestinal ischemia/reperfusion (I/R) induces ER stress, thereby activating the unfolded protein response (UPR), and whether excessive UPR activation affects Paneth cells. In addition, we investigated the consequences of Paneth cell compromise during physical barrier damage.

METHODS

Jejunal I/R was studied using a human experimental model (n = 30 patients). Activation of the UPR was assessed using immunofluorescence for binding protein and quantitative polymerase chain reaction analyses for C/EBP homologous protein (CHOP), growth arrest and DNA-damage inducible protein 34 (GADD34), and X-box binding protein 1 (XBP1) splicing. Paneth cell apoptosis was assessed by double staining for lysozyme and M30. Male Sprague-Dawley rats underwent either intestinal I/R to investigate UPR activation and Paneth cell apoptosis, or hemorrhagic shock with or without intraperitoneal administration of dithizone, to study consequences of Paneth cell compromise during physical intestinal damage. In these animals, bacterial translocation and circulating tumor necrosis factor-α and interleukin-6 levels were assessed.

RESULTS

In jejunum samples from humans and rats, I/R activated the UPR and resulted in Paneth cell apoptosis. Apoptotic Paneth cells showed signs of ER stress, and Paneth cell apoptosis correlated with the extent of ER stress. Apoptotic Paneth cells were shed into the crypt lumen, significantly lowering their numbers. In rats, Paneth cell compromise increased bacterial translocation and inflammation during physical intestinal damage.

CONCLUSIONS

ER stress-induced Paneth cell apoptosis contributes to intestinal I/R-induced bacterial translocation and systemic inflammation.

Human intestinal ischemia-reperfusion-induced inflammation characterized: experiences from a new translational model

Human intestinal ischemia-reperfusion (IR) is a frequent phenomenon carrying high morbidity and mortality. Although intestinal IR-induced inflammation has been studied extensively in animal models, human intestinal IR induced inflammatory responses remain to be characterized. Using a newly developed human intestinal IR model, we show that human small intestinal ischemia results in massive leakage of intracellular components from ischemically damaged cells, as indicated by increased arteriovenous concentration differences of intestinal fatty acid binding protein and soluble cytokeratin 18. IR-induced intestinal barrier integrity loss resulted in free exposure of the gut basal membrane (collagen IV staining) to intraluminal contents, which was accompanied by increased arteriovenous concentration differences of endotoxin. Western blot for complement activation product C3c and immunohistochemistry for activated C3 revealed complement activation after IR. In addition, intestinal IR resulted in enhanced tissue mRNA expression of IL-6, IL-8, and TNF-alpha, which was accompanied by IL-6 and IL-8 release into the circulation. Expression of intercellular adhesion molecule-1 was markedly increased during reperfusion, facilitating influx of neutrophils into IR-damaged villus tips. In conclusion, this study for the first time shows the sequelae of human intestinal IR-induced inflammation, which is characterized by complement activation, production and release of cytokines into the circulation, endothelial activation, and neutrophil influx into IR-damaged tissue.

Localization of the lipopolysaccharide recognition complex in the human healthy and inflamed premature and adult gut

BACKGROUND

Microbiota in the intestinal lumen provide an abundant source of potentially detrimental antigens, including lipopolysaccharide (LPS), a potent immunostimulatory product of Gram-negative bacteria recognized by the host via TLR-4 and MD-2. An aberrant immune response to LPS or other bacterial antigens has been linked to inflammatory bowel disease (IBD) and necrotizing enterocolitis (NEC).

METHODS

We investigated which cells express MD-2 in the normal and inflamed ileum from neonates and adults by immunohistochemistry. Moreover, MD-2 and TLR4 mRNA expression in normal adult ileum was studied by reverse-transcription polymerase chain reaction (RT-PCR) on cells isolated by laser capture microdissection.

RESULTS

Premature infants did not show MD-2 expression either in epithelial cells or in the lamina propria. Similarly, MD-2 was absent in epithelial cells and lamina propria inflammatory cells in preterm infants with NEC. MD-2 protein in the healthy term neonatal and adult ileum was predominantly expressed by Paneth cells and some resident inflammatory cells in the lamina propria. MD-2 and TLR-4 mRNA expression was restricted to crypt cells. Also in IBD, Paneth cells were still the sole MD-2-expressing epithelial cells, whereas inflammatory cells (mainly plasma cells) were responsible for the vast majority of the MD-2 expression.

CONCLUSIONS

The absence of MD-2 in the immature neonatal gut suggests impaired LPS sensing, which could predispose neonates to NEC upon microbial colonization of the immature intestine. The apparent expression of MD-2 by Paneth cells supports the critical concept that these cells respond to luminal bacterial products in order to maintain homeostasis with the intestinal microbiota in vivo.

A new model to study intestinal ischemia-reperfusion damage in man

BACKGROUND

This report describes a human in vivo ischemia reperfusion (IR) model of the small intestine. Animal models of intestinal IR are indispensable for our understanding of sequelae of IR induced organ damage. However, a functional experimental IR model of the human small intestine, allowing for translational research, can be considered critical for our pathophysiologic understanding of intestinal IR in man.

MATERIALS AND METHODS

Patients with a healthy gut undergoing abdominal surgery with a Roux-Y or similar reconstruction were included, creating the opportunity to study IR of an isolated jejunal segment in a harmless model.

RESULTS

Ischemia was induced by nontraumatic vascular clamping followed by reperfusion. This model can be adapted using variable ischemia and reperfusion times. Similarly, tissue and plasma can be collected at any given time point during ischemia until end of reperfusion, only determined by progress of the original, intended surgical procedure.

CONCLUSION

A unique and harmless human IR model of the jejunum was created, which enables the study of acute damage to the epithelial lining and its subsequent repair mechanisms.

Enterocyte shedding and epithelial lining repair following ischemia of the human small intestine attenuate inflammation

Background

Recently, we observed that small-intestinal ischemia and reperfusion was found to entail a rapid loss of apoptotic and necrotic cells. This study was conducted to investigate whether the observed shedding of ischemically damaged epithelial cells affects IR induced inflammation in the human small gut.

Methods and Findings

Using a newly developed IR model of the human small intestine, the inflammatory response was studied on cellular, protein and mRNA level. Thirty patients were consecutively included. Part of the jejunum was subjected to 30 minutes of ischemia and variable reperfusion periods (mean reperfusion time 120 (±11) minutes). Ethical approval and informed consent were obtained. Increased plasma intestinal fatty acid binding protein (I-FABP) levels indicated loss in epithelial cell integrity in response to ischemia and reperfusion (p<0.001 vs healthy). HIF-1α gene expression doubled (p = 0.02) and C3 gene expression increased 4-fold (p = 0.01) over the course of IR. Gut barrier failure, assessed as LPS concentration in small bowel venous effluent blood, was not observed (p = 0.18). Additionally, mRNA expression of HO-1, IL-6, IL-8 did not alter. No increased expression of endothelial adhesion molecules, TNFα release, increased numbers of inflammatory cells (p = 0.71) or complement activation, assessed as activated C3 (p = 0.14), were detected in the reperfused tissue.

Conclusions

In the human small intestine, thirty minutes of ischemia followed by up to 4 hours of reperfusion, does not seem to lead to an explicit inflammatory response. This may be explained by a unique mechanism of shedding of damaged enterocytes, reported for the first time by our group.

High-fat nutrition reduces hepatic damage following exposure to bacterial DNA and hemorrhagic shock

BACKGROUND/AIMS

Bacterial infection combined with hypotension results in exacerbation of the inflammatory response with release of interferon (IFN) gamma. This excessive inflammation may lead to development of hepatic damage and liver failure. This study investigates the effect of dietary lipids on release of IFN-gamma and development of hepatic damage following exposure to synthetic bacterial DNA (CpG-ODN) and hemorrhagic shock.

METHODS

Rats were exposed to CpG-ODN 18h before hemorrhagic shock. Samples were taken 4h following shock. High-fat nutrition was administered at 18h, 2h and 45min before induction of shock.

RESULTS

Enteral high-fat strongly reduced circulating IFN-gamma (0.2ng/ml, P<0.01) following exposure to CpG-ODN and hemorrhagic shock compared with fasted rats (2.7ng/ml). Concomitantly, plasma L-FABP was reduced (437+/-22ng/ml, P<0.01), and F-actin distribution was preserved. Furthermore, high-fat nutrition reduced apoptosis in the liver and preserved expression of the hepatoprotective protein ABIN-1. Interestingly, administration of anti-IFN-gamma antibodies was associated with reduced expression of ABIN-1.

CONCLUSIONS

This study shows that enteral high-fat reduces IFN-gamma and decreases CpG-enhanced liver injury following hemorrhagic shock. Administration of high-fat nutrition may be an important new therapeutic strategy to reduce liver damage in a clinical setting of bacterial infection combined with hypotension.

New Insight in Loss of Gut Barrier during Major Non-Abdominal Surgery

Background

Gut barrier loss has been implicated as a critical event in the occurrence of postoperative complications. We aimed to study the development of gut barrier loss in patients undergoing major non-abdominal surgery.

Methodology/Principal Findings

Twenty consecutive children undergoing spinal fusion surgery were included. This kind of surgery is characterized by long operation time, significant blood loss, prolonged systemic hypotension, without directly leading to compromise of the intestines by intestinal manipulation or use of extracorporeal circulation. Blood was collected preoperatively, every two hours during surgery and 2, 4, 15 and 24 hours postoperatively. Gut mucosal barrier was assessed by plasma markers for enterocyte damage (I-FABP, I-BABP) and urinary presence of tight junction protein claudin-3. Intestinal mucosal perfusion was measured by gastric tonometry (P_rCO₂, P_r-aCO₂-gap). Plasma concentration of I-FABP, I-BABP and urinary expression of claudin-3 increased rapidly and significantly after the onset of surgery in most children. Postoperatively, all markers decreased promptly towards baseline values together with normalisation of MAP. Plasma levels of I-FABP, I-BABP were significantly negatively correlated with MAP at ½ hour before blood sampling (−0.726 (p<0.001), −0.483 (P<0.001), respectively). Furthermore, circulating I-FABP correlated with gastric mucosal P_rCO₂, P_r-aCO₂-gap measured at the same time points (0.553 (p = 0.040), 0.585 (p = 0.028), respectively).

Conclusions/Significance

This study shows the development of gut barrier loss in children undergoing major non-abdominal surgery, which is related to preceding hypotension and mesenterial hypoperfusion. These data shed new light on the potential role of peroperative circulatory perturbation and intestinal barrier loss.

Rapid reversal of human intestinal ischemia-reperfusion induced damage by shedding of injured enterocytes and reepithelialisation

Background

Intestinal ischemia-reperfusion (IR) is a phenomenon related to physiological conditions (e.g. exercise, stress) and to pathophysiological events (e.g. acute mesenteric ischemia, aortic surgery). Although intestinal IR has been studied extensively in animals, results remain inconclusive and data on human intestinal IR are scarce. Therefore, an experimental harmless model for human intestinal IR was developed, enabling us to clarify the sequelae of human intestinal IR for the first time.

Methods and Findings

In 30 patients undergoing pancreatico-duodenectomy we took advantage of the fact that in this procedure a variable length of jejunum is removed. Isolated jejunum (5 cm) was subjected to 30 minutes ischemia followed by reperfusion. Intestinal Fatty Acid Binding Protein (I-FABP) arteriovenous concentration differences across the bowel segment were measured before and after ischemia to assess epithelial cell damage. Tissue sections were collected after ischemia and at 25, 60 and 120 minutes reperfusion and stained with H&E, and for I-FABP and the apoptosis marker M30. Bonferroni's test was used to compare I-FABP differences. Mean (SEM) arteriovenous concentration gradients of I-FABP across the jejunum revealed rapidly developing epithelial cell damage. I-FABP release significantly increased from 290 (46) pg/ml before ischemia towards 3,997 (554) pg/ml immediately after ischemia (p<0.001) and declined gradually to 1,143 (237) pg/ml within 1 hour reperfusion (p<0.001). Directly after ischemia the intestinal epithelial lining was microscopically normal, while subepithelial spaces appeared at the villus tip. However, after 25 minutes reperfusion, enterocyte M30 immunostaining was observed at the villus tip accompanied by shedding of mature enterocytes into the lumen and loss of I-FABP staining. Interestingly, within 60 minutes reperfusion the epithelial barrier resealed, while debris of apoptotic, shedded epithelial cells was observed in the lumen. At the same time, M30 immunoreactivity was absent in intact epithelial lining.

Conclusions

This is the first human study to clarify intestinal IR induced cell damage and repair and its direct consequences. It reveals a unique, endogenous clearing mechanism for injured enterocytes: rapid detachment of damaged apoptotic enterocytes into the lumen. This process is followed by repair of the epithelial continuity within an hour, resulting in a normal epithelial lining.

Liver manipulation causes hepatocyte injury and precedes systemic inflammation in patients undergoing liver resection

Background

Liver failure following liver surgery is caused by an insufficient functioning remnant cell mass. This can be due to insufficient liver volume and can be aggravated by additional cell death during or after surgery. The aim of this study was to elucidate the causes of hepatocellular injury in patients undergoing liver resection.

Methods

Markers of hepatocyte injury (AST, GSTα, and L-FABP) and inflammation (IL-6) were measured in plasma of patients undergoing liver resection with and without intermittent inflow occlusion. To study the separate involvement of the intestines and the liver in systemic L-FABP release, arteriovenous concentration differences for L-FABP were measured.

Results

During liver manipulation, liver injury markers increased significantly. Arterial plasma levels and transhepatic and transintestinal concentration gradients of L-FABP indicated that this increase was exclusively due to hepatic and not due to intestinal release. Intermittent hepatic inflow occlusion, anesthesia, and liver transection did not further enhance arterial L-FABP and GSTα levels. Hepatocyte injury was followed by an inflammatory response.

Conclusions

This study shows that liver manipulation is a leading cause of hepatocyte injury during liver surgery. A potential causal relation between liver manipulation and systemic inflammation remains to be established; but since the inflammatory response is apparently initiated early during major abdominal surgery, interventions aimed at reducing postoperative inflammation and related complications should be started early during surgery or beforehand.

EVIDENCE FOR INTESTINAL AND LIVER EPITHELIAL CELL INJURY IN THE EARLY PHASE OF SEPSIS

The development of sepsis and multiple organ failure are important determinants of the outcome in critically ill patients. Hepatosplanchnic hypoperfusion and resulting intestinal and hepatic cell damage have been implicated as central events in the development of sepsis and multiple organ failure. Our aim was to study (1) the relation between intramucosal perfusion and intestinal and hepatic cell damage in an early phase of sepsis and (2) the correlation of these parameters with mortality. Two groups of patients were consecutively selected after intensive care unit admission: patients with postoperative abdominal sepsis (n = 19) and patients with pneumonia-induced sepsis (n = 9). Intramucosal perfusion was assessed by gastric tonometry (Pr-aCO2 gap, Pico2). Circulating levels of intestinal fatty acid binding protein (I-FABP) and liver (L)-FABP were used as markers for intestinal and hepatic cellular damage, respectively. Outcome was determined on day 28. Pr-aCO2 gap correlated with I-FABP (Pearson r = 0.56; P < 0.001) in all patients, and gastric mucosal Pico2 correlated significantly with I-FABP (r = 0.57; P = 0.001) in patients with abdominal sepsis. At intensive care unit admission, nonsurvivors had significantly higher I-FABP and L-FABP values than survivors (I-FABP: 325 vs. 76 pg/mL, P < 0.04; L-FABP: 104 vs. 31 ng/mL, P < 0.04). Patients with abdominal sepsis was especially responsible for high-admission I-FABP and L-FABP levels in nonsurvivors (I-FABP: 405 vs. 85 pg/mL, P < 0.04; L-FABP: 121 vs. 59 ng/mL, P < 0.04). This study shows that splanchnic hypoperfusion correlates with intestinal mucosal damage, and that elevated plasma levels of I-FABP and L-FABP are associated with a poor outcome in critically ill patients with abdominal sepsis.

Long-term functional sequelae of sacrococcygeal teratoma: a national study in The Netherlands

BACKGROUND

Long-term functional sequelae after resection of sacrococcygeal teratoma (SCT) are relatively common. This study determines the incidence of these sequelae associated clinical variables and its impact on quality of life (QoL).

PATIENTS AND METHODS

Patients with SCT treated from 1980 to 2003 at the pediatric surgical centers in The Netherlands aged more than 3 years received age-specific questionnaires, which assessed parameters reflecting bowel function (involuntary bowel movements, soiling, constipation), urinary incontinence, subjective aspect of the scar, and QoL. These parameters were correlated with clinical variables, which were extracted from the medical records. Risk factors were identified using univariate analysis.

RESULTS

Of the 99 posted questionnaires, 79 (80%) were completed. The median age of the patients was 9.7 years (range, 3.2-22.6 years). There were 46% who reported impaired bowel function and/or urinary incontinence (9% involuntary bowel movements, 13% soiling, 17% constipation), and 31% urinary incontinence. In 40%, the scar was cosmetically unacceptable. Age at completion of the questionnaire, Altman classification, sex, and histopathology were not risk factors for any long-term sequelae. Size of the tumor (>500 cm3) was a significant risk factor for cosmetically unacceptable scar (odds ration [OR], 4.73; confidence limit [CL], 1.21-18.47; P = .026). Long-term sequelae were correlated with diminished QoL.

CONCLUSION

A large proportion of the patients with SCT have problems with defecation, urinary incontinence, or a cosmetically unacceptable scar that affects QoL. Patients who are at higher risk for the development of long-term sequelae cannot be clearly assessed using clinical variables.

Factors associated with recurrence and metastasis in sacrococcygeal teratoma

Background

Sacrococcygeal teratoma (SCT) is a relatively uncommon tumour, with a high risk of recurrence and metastasis. The factors associated with recurrence and metastatic disease were studied.

Methods

A retrospective review was conducted of 173 children with SCT treated between January 1970 and February 2003 at the paediatric surgical centres in the Netherlands. Risk factors were identified by univariate and multivariate analysis.

Results

Eight children died shortly after birth or around the time of operation. Nine children, all over 18 months old, had metastases at presentation. Four teratomas with metastasis showed mature histology of the primary tumour. Nineteen children had recurrence of SCT a median interval of 10 months (range 32 days to 35 months) after primary surgery. Risk factors for recurrence were pathologically confirmed incomplete resection (odds ratio (OR) 6·54 (95 per cent confidence interval (c.i.) 2·11 to 20·31)), immature histology (OR 5·74 (95 per cent c.i. 1·49 to 22·05)) and malignant histology (OR 12·83 (95 per cent c.i. 3·27 to 50·43)). Size, Altman classification, age and decade of diagnosis were not risk factors for recurrence. One-third of the recurrences showed a shift towards histological immaturity or malignancy, compared with the primary tumour. Seven patients died after recurrence, five with malignant disease.

Conclusion

This national study showed that SCT recurred in 11 per cent of the children within 3 years of operation. Risk factors were immature and malignant histology, or incomplete resection. Mature teratoma has the biological capability to become malignant.