Characterization of gastric dysfunction after fundoplication using body surface gastric mapping.

BACKGROUND: Adverse gastric symptoms persist in up to 20% of fundoplication operations completed for gastroesophageal reflux disease, causing significant morbidity and driving the need for revisional procedures. Noninvasive techniques to assess the mechanisms of persistent postoperative symptoms are lacking. This study aimed to investigate gastric myoelectrical abnormalities and symptoms in patients after fundoplication using a novel noninvasive body surface gastric mapping (BSGM) device. METHODS: Patients with a previous fundoplication operation and ongoing significant gastroduodenal symptoms and matched controls were included. BSGM using Gastric Alimetry (Alimetry Ltd) was employed, consisting of a high-resolution 64-channel array, validated symptom-logging application, and wearable reader. RESULTS: A total of 16 patients with significant chronic symptoms after fundoplication were recruited, with 16 matched controls. Overall, 6 of 16 patients (37.5%) showed significant spectral abnormalities defined by unstable gastric myoelectrical activity (n = 2), abnormally high gastric frequencies (n = 3), or high gastric amplitudes (n = 1). Patients with spectral abnormalities had higher Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index scores than those of patients without spectral abnormalities (3.2 [range, 2.8-3.6] vs 2.3 [range, 2.2-2.8], respectively; P = .024). Moreover, 7 of 16 patients (43.8%) had BSGM test results suggestive of gut-brain axis contributions and without myoelectrical dysfunction. Increasing Principal Gastric Frequency Deviation and decreasing Rhythm Index scores were associated with symptom severity (r > .40; P < .05). CONCLUSION: A significant number of patients with persistent postfundoplication symptoms displayed abnormal gastric function on BSGM testing, which correlated with symptom severity. Our findings advance the pathophysiologic understanding of postfundoplication disorders, which may inform diagnosis and patient selection for medical therapy and revisional procedures.

Effect of Banded Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy on Diabetes Remission at 5 Years Among Patients With Obesity and Type 2 Diabetes: A Blinded Randomized Clinical Trial.

OBJECTIVE: To determine whether silastic ring laparoscopic Roux-en-Y gastric bypass (SR-LRYGB) or laparoscopic sleeve gastrectomy (LSG) produces superior diabetes remission at 5 years. RESEARCH DESIGN AND METHODS: In a single-center, double-blind trial, 114 adults with type 2 diabetes and BMI 35-65 kg/m2 were randomly assigned to SR-LRYGB or LSG (1:1; stratified by age-group, BMI group, ethnicity, diabetes duration, and insulin therapy) using a web-based service. Diabetes and other metabolic medications were adjusted according to a prespecified protocol. The primary outcome was diabetes remission assessed at 5 years, defined by HbA1c <6% (42 mmol/mol) without glucose-lowering medications. Secondary outcomes included changes in weight, cardiometabolic risk factors, quality of life, and adverse events. RESULTS: Diabetes remission after SR-LRYGB versus LSG occurred in 25 (47%) of 53 vs. 18 (33%) of 55 patients (adjusted odds ratios 4.5 [95% CI 1.6, 15.5; P = 0.009] and 4.2 [1.3, 13.4; P = 0.015] in the intention-to-treat analysis). Percent body weight loss was greater after SR-LRYGB than after LSG (absolute difference 10.7%; 95% CI 7.3, 14.0; P < 0.001). Improvements in cardiometabolic risk factors were similar, but HDL cholesterol increased more after SR-LRYGB. Early and late complications were similar in both groups. General health and physical functioning improved after both types of surgery, with greater improvement in physical functioning after SR-LRYGB. People of Maori or Pacific ethnicity (26%) had lower incidence of diabetes remission than those of New Zealand European or other ethnicities (2 of 25 vs. 41 of 83; P < 0.001). CONCLUSIONS: SR-LRYGB provided superior diabetes remission and weight loss compared with LSG at 5 years, with similar low risks of complications.

Impact of Bariatric Surgery on Unplanned Hospital Admissions for Infection.

PURPOSE: Both obesity and type 2 diabetes are associated with an increased risk of skin and soft tissue (SSTI), urinary tract, and lower respiratory tract infections but it is not clear whether the incidence of such infections is reduced after bariatric surgery. MATERIALS AND METHODS: In people accepted onto our publicly funded bariatric program, we recorded unplanned admissions to public hospitals over a median follow-up of 4.5 years in those successfully undergoing surgery and in those who withdrew from the program. Rates of admission for the composite outcome (SSTI, urinary tract, or lower respiratory infection) were compared. RESULTS: Of 774 people accepted onto the program, 49% underwent surgery. Infections accounted for 27% of unplanned admissions in those not completing surgery and 13% of those who underwent surgery (p < 0.001). The rate of admission was 60% lower in people who underwent surgery than those who did not: 4.3 vs 12.2 per 100 patient-years (P < 0.002), a difference maintained across 8 years' follow-up. The impact of surgery was independent of enrolment age, BMI, or diabetes and smoking status. Of the three types of infection in the composite outcome, SSTI were the most prevalent and showed the greatest reduction (p < 0.0001). The median day stay for infection was 0.5 day less in those who underwent surgery (p < 0.01). CONCLUSIONS: Hospitalization for these three infectious diseases in people undergoing bariatric surgery was lower than that in people enrolled in the bariatric program but not completing surgery. The effect was greatest for SSTI, and sustained to at least 8 years.

Insulin use and new diabetes after acceptance for bariatric surgery: comparison of outcomes after completion of surgery or withdrawal from the program.

INTRODUCTION: In people accepted onto a bariatric surgery program we compared diabetes-related outcomes in those who completed surgery with those who withdrew before having surgery-examining rates of insulin use in people with type 2 diabetes (T2D), and rates of incident diabetes in people without pre-existing T2D. RESEARCH DESIGN AND METHODS: 771 people were accepted onto the program. 463 people (60%) had T2D at referral, of which 48% completed surgery and 52% withdrew. Of 308 people without T2D at referral, 49% completed surgery, and 51% withdrew. Rates of insulin use and incident diabetes were compared by Kaplan-Meier analyses. Among those with pre-existing T2D, we examined rates of remission and relapse after surgery. RESULTS: People without T2D who withdrew from the program had higher mean body mass index and glycated hemoglobin levels than those completing surgery (p<0.005). The rate of incident diabetes at 5 years was 19% in those who withdrew versus 0% in those completing surgery (p<0.001). 30% of people with T2D were taking insulin at referral and all stopped insulin after surgery. During follow-up, the rate of insulin (re)introduction was lower in those who completed surgery (8% vs 26% at 5 years, p<0.001). Of those with T2D who completed surgery, 80% had remission, but 34% had relapsed by 5 years. Diabetes relapse was associated with less weight loss after surgery, a longer duration of T2D and previous insulin use. CONCLUSIONS: Despite a high relapse rate, people with T2D who completed surgery had lower insulin use at 5 years than those withdrawing from the program. In people without T2D, bariatric surgery prevented incident diabetes. People without T2D who withdrew from the program were at greater risk of diabetes, suggesting those who could benefit the most in terms of T2D prevention are not completing bariatric surgery.

Safety and Utility of Liver Biopsy During Bariatric Surgery in the New Zealand Setting.

BACKGROUND: Asymptomatic liver disease is common in bariatric patients and can be diagnosed with intraoperative biopsy. This study aimed to establish the risk-benefit profile of routine liver biopsy, prevalence of clinically significant liver disease, relationship between liver pathology and body mass index, and compare outcomes between ethnic groups. METHODS: This retrospective cohort study included all patients who had index bariatric surgery at Auckland City Hospital between 2009 and 2016. Diagnosis of liver disease was based on intraoperative biopsy histology. Outcomes included safety (biopsy-related complication) and utility (liver pathology meeting criteria for referral). Liver pathology and referral rates were compared between ethnic groups. RESULTS: Of 335 bariatric surgery patients, 234 (70%) underwent intraoperative liver biopsy. There were no biopsy-related complications. Histological findings were as follows: normal 25/234 (11%), non-alcoholic fatty liver disease (NAFLD) 207/234 (88%), and other pathological findings in 35/234 (15%). Histological finding meeting referral criteria was present in 22/234 (9%). Of these, 12/22 (55%) were referred. Number needed to biopsy to identify histology meeting referral criteria: n = 11. Maori had a similar NAFLD rate to non-Maori [51/56 versus 156/178, p = 0.48]. Pasifika patients had a higher rate than non-Pasifika [39/40 versus 168/194, p = 0.049]. Maori and Pasifika patients had similar referral rates to non-Maori and non-Pasifika [2/3 versus 5/9, p = 0.73; 2/2 versus 5/10, p = 0.19]. CONCLUSIONS: Intraoperative liver biopsy during bariatric surgery is safe and identified liver disease in 89%, with 9% meeting referral criteria. Pasifika patients have a higher rate of NAFLD than non-Pasifika.

Pre-operative Bariatric Clinic Attendance Is a Predictor of Post-operative Clinic Attendance and Weight Loss Outcomes.

AIM: Our primary aim was to determine whether non-attendance at pre-operative clinics were associated with non-attendance at post-operative clinics and its influence on weight loss. We also sought to examine the relationship between gender, ethnicity and post-operative clinic attendance with respect to weight loss post-bariatric surgery. METHODS: A retrospective audit was performed for patients undertaking the bariatric surgery program at the Auckland City Hospital between 2013 and 2016. RESULTS: One hundred and eighty-four patients completed our program, with a mean age of 46.1 years. Mean weight at commencement was 133.3 kg, with a BMI of 47.4. At 2 years follow-up (n = 143), excess weight loss was 70.8% following RYGB and 68.0% following LSG (p = 0.5743). More patients attended all pre-operative than post-operative clinics (67.4% vs 37.5% p = < 0.001). One pre-operative clinic non-attendance was associated with less weight loss at 2 years and it increases the risk of missing at least 50% of post-operative clinics with a risk ratio of 2.73, p = 0.005. Non-attendance of at least 50% of post-operative clinics was also associated with less weight loss at 2 years (33.4 kg vs 44.3 kg, p = 0.040). Although Maori and Pacific Islanders more frequently missed > 50% of post-operative clinics, weight loss was similar between European, Maori and Pacific Islander populations (2-year weight loss 44.2 kg vs 40.74 kg vs 44.1 kg, respectively, p = 0.8192). CONCLUSION: Pre-operative clinic non-attendance helps predict post-operative clinic non-attendance. Missing any pre-operative clinics and at least 50% of scheduled post-operative clinics is associated with poorer weight loss outcomes.

The Pathogenesis of Nonocclusive Mesenteric Ischemia: Implications for Research and Clinical Practice.

Nonocclusive mesenteric ischemia (NOMI) is a condition that can encompass ischemia, inflammation, and infarction of the intestinal wall. In contrast to most patients with acute mesenteric ischemia, NOMI is distinguished by patent arteries and veins. The clinical presentation of NOMI is often insidious and nonspecific, resulting in a delayed diagnosis. Patients most at risk are those with severe acute and critical disease, including major surgery and trauma. Nonocclusive mesenteric ischemia is part of a spectrum, from mild, asymptomatic, and an unexpected finding on CT scanning, through to those exhibiting abdominal distension and peritonitis. Severe NOMI is associated with a significant mortality rate. This review of NOMI pathophysiology was conducted to document current concepts and evidence, to examine the implications for diagnosis and treatment, and to identify gaps in knowledge that might direct future research. The key pathologic mechanisms involved in the genesis of NOMI represent an exaggerated normal physiological response to maintain perfusion of vital organs at the expense of mesenteric perfusion. A supply-demand mismatch develops in the intestine due to the development of persistent mesenteric vasoconstriction resulting in reduced blood flow and oxygen delivery to the intestine, particularly to the vulnerable superficial mucosa. This mismatch can be exacerbated by raised intra-abdominal pressure, enteral nutrition, and the use of certain vasoactive drugs, ultimately resulting in the development of intestinal ischemia. Strategies for prevention, early detection, and treatment are urgently needed.

Correction to: Attrition after Acceptance onto a Publicly Funded Bariatric Surgery Program.

Unfortunately, the original version of this article contained an error. The Methods section's first sentence and Table 1 both mistakenly contained the letters XXXX in place of the district health board and hospital city names.

Attrition after Acceptance onto a Publicly Funded Bariatric Surgery Program.

BACKGROUND: Factors such as ethnicity, gender, and socioeconomic status may play a role in both access to and attrition from bariatric programs before surgery is undertaken. New Zealand (NZ) has high rates of obesity in its Pacific population and the indigenous Maori. These groups also experience poorer health outcomes and therefore have the greatest need for surgery. METHODOLOGY: A retrospective cross-sectional study of 704 people referred for and accepted onto a publicly funded bariatric surgery from 2007 to 2016. The demographic and clinical features of two groups were compared: those that completed surgery successfully (n = 326) and those that dropped out of the program before surgery (n = 378). We also attempted to identify factors associated with attrition. RESULTS: The attrition rate was high (54%), with a significant difference according to gender (men 66% vs 45% women, p < 0.001) and ethnicity (39% in NZ Europeans, 50% in Maori, and 73% in Pacific patients, p < 0.001). Two out of three European women proceeded to surgery, but fewer than one in seven Pacific men. Attrition was associated with having a higher mean BMI and being a smoker. Logistic regression modeling showed that while employment seemed to be protective against attrition for NZ Europeans (p < 0.004), it was not for Pacific patients. CONCLUSIONS: While there was no obvious bias in rates of referral, there is clearly a need for better ways to support Maori and Pacific people, and men in particular, to complete bariatric surgery. Further research is needed to clarify the socio-economic and cultural barriers that underlie this phenomenon.

Laparoscopic Sleeve Gastrectomy Versus Banded Roux-en-Y Gastric Bypass for Diabetes and Obesity: a Prospective Randomised Double-Blind Trial.

BACKGROUND: There are very few randomised, blinded trials comparing laparoscopic sleeve gastrectomy (LSG) versus laparoscopic Roux-en-Y gastric bypass (LRYGB) in achieving remission of type 2 diabetes (T2D), particularly silastic ring (SR)-LRYGB. We compared the effectiveness of (LSG) versus SR-LRYGB among patients with T2D and morbid obesity. METHODS: Prospective, randomised, parallel, 2-arm, blinded clinical trial conducted in a single Auckland (New Zealand) centre. Eligible patients aged 20-55 years, T2D of at least 6 months duration and BMI 35-65 kg/m2 were randomised 1:1 to LSG (n = 58) or SR-LRYGB (n = 56) using random number codes disclosed after anaesthesia induction. Primary outcome was T2D remission defined by different HbA1c thresholds at 1 year. Secondary outcomes included weight loss, quality of life, anxiety and depressive symptoms, post-operative complications and mortality. RESULTS: Mean ± standard deviation (SD) pre-operative BMI was 42.5 ± 6.2 kg/m2, HbA1c 63 ± 16 mmol/mol (30% insulin-treated, 28% had diabetes duration over 10 years). Proportions achieving HbA1c ≤ 38 mmol/mol, < 42 mmol/mol, < 48 mmol/mol and < 53 mmol/mol without diabetes medication at 1 year in SR-LRYGB vs LSG were 38 vs 43% (p = 0.56), 52 vs 49% (p = 0.85), 75 vs 72% (p = 0.83) and 80 vs 77% (p = 0.82), respectively. Mean ± SD % total weight loss at 1 year was greater after SR-LRYGB than LSG: 32.2 ± 7.7 vs 27.1 ± 7.5%, respectively (p < 0.001). Gastrointestinal complications were more frequent after SR-LRYGB (including 3 ulcers, 1 anastomotic leak, 1 abdominal bleeding). Quality of life and depression symptoms improved significantly in both groups. CONCLUSION: Despite significantly greater weight loss after SR-LRYGB, there was similar T2D remission and psychosocial improvement after LSG and SR-LRYGB at 1 year. TRIAL REGISTRATION: Prospectively registered at Australia and New Zealand Clinical Trials Register (ACTRN 12611000751976) and retrospectively registered at Clinical Trials (NCT1486680).

Nonocclusive mesenteric infarction after cardiac surgery: potential biomarkers.

BACKGROUND: Nonocclusive mesenteric ischemia can cause intestinal infarction but the diagnosis is challenging. This prospective study evaluated three plasma biomarkers of intestinal infarction after cardiac surgery. MATERIALS AND METHODS: Patients were recruited after cardiac surgery if they required laparotomy (with or without intestinal resection) for suspected nonocclusive mesenteric ischemia. Plasma levels of D-lactate, intestinal fatty acid-binding protein (i-FABP), and smooth muscle actin (SMA) before laparotomy were measured. RESULTS: Twenty patients were recruited (68 ± 9 y, EuroSCORE: 8.7 ± 2.8, mortality 70%). A positive laparotomy (n = 13) was associated with no change in D-lactate (P = 0.95), decreased i-FABP (P = 0.007), and increased SMA (P = 0.01). All patients with high SMA had a positive laparotomy. A subgroup analysis was undertaken in the eight patients who required multiple laparotomies. D-lactate increased between the two laparotomies in nonsurvivors (n = 4). Plasma i-FABP (P = 0.008) and SMA (P = 0.036) significantly decreased after the bowel resection, regardless of survival outcome. CONCLUSIONS: None of the biomarkers were accurate enough to reliably diagnose intestinal infarction. However, all patients with high values of SMA developed intestinal infarction, thus warranting further investigation. An increasing D-lactate after intestinal resection suggests impending death.

Costs of bariatric surgery in a randomised control trial (RCT) comparing Roux en Y gastric bypass vs sleeve gastrectomy in morbidly obese diabetic patients.

AIM: To provide a longitudinal analysis of the direct healthcare costs of providing laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery service in the context of a randomised control trial (RCT) of obese patients with type 2 diabetes in Waitemata District Health Board, Auckland, New Zealand. METHODS: The Waitemata District Health Board costing system was used to calculate costs in New Zealand Dollars (NZD) associated with all pre- and post-operative hospital clinic visits, peri-operative care, hospitalisations and medication costs up to one year after bariatric surgery. Healthcare costs of medications, laboratory investigations and hospital clinic visits for one year prior to enrolment into the RCT were also calculated. RESULTS: One hundred and fourteen patients were randomised to undergo laparoscopic sleeve gastrectomy (LSG, n=58) or laparoscopic Roux en Y gastric bypass (LRYGB, n=56). Total costs one year pre-enrolment was $203,926 for all patients (mean $1,789 per patient). Total cost of surgery was $1,208,005 (mean $9,131 per LSG patient and mean $12,456 per LRYGB patient). Total cost one year post-operatively was $542,656 (mean $4,760 per patient). The total medication cost reduced from $118,993.72(mean $1,044 per patient) to $31,304.93 (mean $274.60 per patient), p<0.005. The largest cost reduction was seen with annual diabetic medications reducing from $110,115.78(mean $965.93 per patient) to $7,237.85 (mean $63.48 per patient), p<0.005. CONCLUSIONS: Among patients with type 2 diabetes and morbid obesity undergoing LSG and LRYGB, health service costs were greater in the year after surgery than in the year before, although prescription costs were lower post-operatively. There was no significant difference in reduction in prescription cost by surgical procedure at 12 months. However, the LRYGB surgery was more expensive than LSG, primarily because of the longer operative time required.

Sleeve gastrectomy versus Roux-en-Y gastric bypass for type 2 diabetes and morbid obesity: double-blind randomised clinical trial protocol.

INTRODUCTION: Type 2 diabetes (T2D) in association with obesity is an increasing disease burden. Bariatric surgery is the only effective therapy for achieving remission of T2D among those with morbid obesity. It is unclear which of the two most commonly performed types of bariatric surgery, laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB), is most effective for obese patients with T2D. The primary objective of this study is to determine whether LSG or LRYGB is more effective in achieving HbA1c<6% (<42 mmol/mol) without the use of diabetes medication at 5 years. METHODS AND ANALYSIS: Single-centre, double-blind (assessor and patient), parallel, randomised clinical trial (RCT) conducted in New Zealand, targeting 106 patients. Eligibility criteria include age 20-55 years, T2D of at least 6 months duration and body mass index 35-65 kg/m(2) for at least 5 years. Randomisation 1:1 to LSG or LRYGB, used random number codes disclosed to the operating surgeon after induction of anaesthesia. A standard medication adjustment schedule will be used during postoperative metabolic assessments. Secondary outcomes include proportions achieving HbA1c<5.7% (39 mmol/mol) or HbA1c<6.5% (48 mmol/mol) without the use of diabetes medication, comparative weight loss, obesity-related comorbidity, operative complications, revision rate, mortality, quality of life, anxiety and depression scores. Exploratory outcomes include changes in satiety, gut hormone and gut microbiota to gain underlying mechanistic insights into T2D remission. ETHICS AND DISSEMINATION: Ethics approval was obtained from the New Zealand regional ethics committee (NZ93405) who also provided independent safety monitoring of the trial. Study commenced in September 2011. Recruitment completed in October 2014. Data collection is ongoing. Results will be reported in manuscripts submitted to peer-reviewed journals and in presentations at national and international meetings. TRIAL REGISTRATION NUMBERS: ACTRN12611000751976, NCT01486680; Pre-results.

Smooth muscle actin as a novel serologic marker of severe intestinal damage in rat intestinal ischemia-reperfusion and human necrotising enterocolitis.

BACKGROUND: Despite emergence of markers of intestinal mucosal damage such as intestinal fatty-acid binding protein (i-FABP), there are no specific markers of damage extending into the muscle layers. We hypothesized that smooth muscle actin (SMA) released from the intestinal muscularis would be detectable in plasma after severe intestinal injury. MATERIALS AND METHODS: Serial blood samples were collected from rats (n = 10) undergoing intestinal ischemia-reperfusion injury (IRI) and controls (n = 5). Additionally, admission and/or preoperative plasma samples were collected from twelve neonates with necrotizing enterocolitis (NEC), and five age- and weight-matched controls. Plasma ileal fatty-acid binding protein (rat) or i-FABP (human) were measured by enzyme-linked immunosorbent assay, and plasma SMA was detected by western blotting. RESULTS: Plasma ileal fatty-acid binding protein was low in both the control group and IRI at baseline, but became rapidly elevated in the IRI group even during ischemia. SMA was detected in reperfusion plasma samples of all IRI rats, but in none of the control samples. Plasma i-FABP was higher in infants with NEC than age- and weight-matched controls. Although i-FABP was higher in infants with severe surgical disease compared with focal disease, there was no difference between the operative and nonoperative groups. SMA was detected in the plasma of all four neonates with severe surgical NEC, but not in those with focal disease or those who were successfully conservatively managed. CONCLUSIONS: SMA is detectable in plasma after severe intestinal injury and maybe a clinically useful maker of intestinal muscle damage.

Urinary intestinal fatty acid-binding protein concentration predicts extent of disease in necrotizing enterocolitis.

PURPOSE: Urinary intestinal fatty acid-binding protein (i-FABP), a marker of intestinal mucosal cell damage, has recently been proposed as a clinically useful measure in the early detection of necrotizing enterocolitis (NEC). However, there are no data on urinary i-FABP in more advanced (Bell stage II /III) NEC. The aim of this study was to test the use of urinary i-FABP in surgical NEC. METHODS: Urine was collected every 24 hours from infants with Bell stage II/III NEC admitted to a surgical Neonatal Intensive Care Unit. Clinical, laboratory, and surgical data were collected concurrently. Urinary i-FABP was quantified by enzyme-linked immunosorbent assay and expressed as picograms per nanomole creatinine (median [range]). Results are presented as median (range) and compared by Mann-Whitney test and by linear regression. RESULTS: There was a trend toward an increase in i-FABP:Cr in infants with NEC (controls, 1.0 [0.4-1.3], vs NEC, 2.1 [0.39-35.1], P = .055). Urinary i-FABP:Cr was significantly higher in infants with extensive disease (7.4 pg/mmol [2.1-35.0 pg/mmol]) than in those with focal disease (1.1 pg/mmol [0.3-1.7 pg/mmol]), P = .002. In addition, i-FABP:Cr was less than the previously suggested 2 pg/mmol cutoff in 6 of 16 infants with NEC, 5 of whom had focal disease. Urinary i-FABP:Cr decreased during both successful nonoperative management (P < .0001) and after surgery in the operated group. CONCLUSIONS: In this pilot study, urinary i-FABP was associated with extensive disease in infants with NEC requiring surgery. Further work, in a larger number of patients, is required to investigate the applicability of urinary i-FABP as a marker of intestinal damage and as an adjunct to current indications for surgical intervention in infants with NEC.

A systematic review of serologic tests in the diagnosis of necrotizing enterocolitis.

BACKGROUND: Although many serologic markers have been suggested for diagnosis of necrotizing enterocolitis, there is little consensus on which of these is potentially clinically useful. Our aims were (i) to systematically review circulating markers that are potentially useful in the diagnosis of NEC and (ii) to compare the relative performance of each serologic marker of NEC by pooling estimates of marker accuracies and presenting their combined diagnostic accuracies. METHODS: We undertook a systematic review of the literature to identify studies that reported serologic markers at the time of diagnosis of necrotizing enterocolitis. Where possible, we constructed 2-by-2 tables of diagnostic accuracy from each article, if 2 or more studies investigated the same test, their results were meta-analyzed by pooling estimates of sensitivity, specificity, likelihood ratio for positive index test (LR+), likelihood ratio for negative index test (LR-), diagnostic odds ratio, and their corresponding 95% confidence intervals. RESULTS: Twenty-five articles provided information on serology at the time of diagnosis of necrotizing enterocolitis. Of these, it was possible to construct diagnostic accuracy tables from 16 articles and to combine data from studies that used C-reactive protein, intestinal fatty acid binding protein, and platelet-activating factor. Of these C-reactive protein was a sensitive but nonspecific marker for necrotizing enterocolitis, whereas platelet-activating factor and intestinal fatty acid binding protein were both sensitive and specific. CONCLUSIONS: Most serologic markers of necrotizing enterocolitis have been used in too few studies to evaluate their use. Of those tests that have been tested repeatedly, platelet-activating factor and intestinal fatty acid binding protein are potentially useful, although their use must be further tested in larger prospective studies.

Systematic review and pooled estimates for the diagnostic accuracy of serological markers for intestinal ischemia.

BACKGROUND: Intestinal ischemia is a potentially catastrophic abdominal emergency that presents a significant diagnostic challenge in the critical care setting. We performed a systematic review of the literature to define the diagnostic accuracy of serological markers of intestinal ischemia. METHODS: Observational studies on the performance of markers of intestinal ischemia were identified within the MEDLINE and EMBASE electronic databases. All studies from which it was possible to derive true positive, false positive, false negative, and true negative results were included. A random-effects model was used to calculate the pooled estimates of diagnostic accuracy. RESULTS: A total of 20 articles examining 18 different serological markers were identified that met the inclusion criteria. The global measures of test performance (diagnostic odds ratio and area under the summary receiver operating characteristic curve) for markers investigated in three or more studies were D-lactate (10.75 and 0.86, respectively), glutathione S-transferase (GST; 8.82 and 0.87, respectively), intestinal fatty-acid binding protein (i-FABP; 7.62 and 0.78, respectively), and D-dimer (5.77 and 0.53, respectively). CONCLUSIONS: The performance of the currently available serological markers is suboptimal for routine clinical use, but novel markers of intestinal ischemia such as D-lactate, GST, and i-FABP may offer improved diagnostic accuracy. The early diagnosis of intestinal ischemia remains a challenge, and further research is required to identify improved serological markers and to demonstrate their clinical utility in the individual patient.