Abdominal computed tomography for diagnosing postoperative lower gastrointestinal tract leaks

The role of radiology in diagnosing gastrointestinal tract perforation

Spontaneous, iatrogenic or surgical perforation of the whole gastrointestinal wall can lead to serious complications, resulting in increased morbidity and mortality. Optimal patient management requires early clinical appraisal and prompt imaging evaluation. Both radiologists and referring clinicians should recognize the importance of choosing the ideal imaging modality and the usefulness of oral and rectal contrast medium. Surgeons and radiologists should be familiar with CT and fluoroscopy findings of the normal and pathologic anatomy after esophageal, stomach or colon surgery. Specifically, they should be able to differentiate innocuous from clinically-relevant, life-threatening postoperative complications to guide appropriate treatment. Advantages of esophagram, CT-esophagram, CT after rectal contrast enema and other imaging modalities are discussed.

Added value of positive intraluminal contrast CT over fluoroscopic examination for detecting gastrointestinal leakage after gastrointestinal surgery

We aimed to evaluate the added value of positive intraluminal contrast computed tomography (CT) over fluoroscopy in detecting anastomotic leakage after gastrointestinal (GI) surgery. A total of 141 GI surgery patients who underwent fluoroscopic examination and CT were included. Two radiologists reviewed the fluoroscopic images with and without CT to determine anastomotic leakage on a 5-point confidence scale and graded the leakage on a 4-point grading system. The hospital stay duration and treatment type were recorded. The radiologists' diagnostic performance in determining leakage was compared using the receiver operating characteristics analysis, and interobserver agreement was analyzed. Fifty-three patients developed GI leakage. When CT was added to the fluoroscopic images, the area under the curve (AUC) values significantly increased for both reviewers. The interobserver agreement for leakage between the two reviewers was excellent and improved with the addition of CT (weighted kappa value, 0.869 versus 0.805). Postoperative intervention was more frequently performed (P < 0.001), and patients with leakage had a significantly longer mean postoperative hospital stay (45 days vs. 27 days) (P = 0.003). Thus, positive intraluminal contrast CT provides added value over fluoroscopic examination for detecting GI leakage in patients undergoing GI tract surgery, increasing AUC values, and improving interobserver agreement.

MRI diagnose post-operative anastomotic leak in patients with rectal cancer: preliminary experience

BACKGROUND

Anastomotic leakage (AL) is one of the most serious postoperative complications after colorectal anastomosis. This study aims to evaluate the feasibility and diagnostic accuracy of magnetic resonance imaging (MRI) in the early detection of AL in patients with clinically suspected AL after rectal anterior resection.

METHODS

This was a prospective study including patients who underwent anterior resection and postoperative MRI examination. AL was diagnosed by comprehensive indictors, which were mainly confirmed by clinical signs, symptoms, and retrograde contrast enema (RCE) radiography. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of diagnosing AL with MRI were calculated.

RESULTS

In total, 347 patients received anterior resection for rectal cancer, and 28 patients were suspected to have AL. Finally, 23 patients were included and received MRI examination. The median time interval from surgery to MRI was 10 days (3-21 days). The median distance from anastomosis to anal verge was 4.0 cm (2.0-10 cm), and 11 patients underwent diverted ileostomy. Eighteen patients had an anastomotic leak, including one patient who had a pelvic abscess and five patients who had no evidence of AL in the MRI examination. The overall sensitivity and specificity were 94.4% (95% CI 70.6% to 99.7%) and 80% (95% CI 29.8% to 98.9%), respectively. The PPV was 0.94 (95% CI 0.71 to 0.99) and the NPV was 0.80 (95% CI 0.29 to 0.99). For patients who had anastomosis less than 5 cm, the diagnostic accuracy of MRI was 93.7% (15/16). T2-weighted imaging with fat suppression can effectively reveal the leak track.

CONCLUSIONS

The accuracy of plain MRI examination in diagnosing AL was favorable for patients with a suspected AL. T2-weighted imaging with fat suppression was the best imaging modality to diagnose AL. A multicenter prospective study with more samples is needed to further determine the safety and feasibility of MRI in the diagnosis of AL.

Early prediction of anastomotic leakage after laparoscopic rectal surgery using creactive protein

At present, anterior resection of the rectum or transabdominal rectal resection is the most common surgical technique for rectal cancer. Laparoscopic techniques are popular, and the efficacy and safety of laparoscopic rectal surgery have been confirmed. However, postoperative anastomotic leakage is a common, severe complication that leads to high mortality. Thus, early diagnosis of anastomotic leakage is important for reducing clinical consequences.The aim of this study was to determine whether C-reactive protein (CRP) is a good predictor of anastomotic leakage in laparoscopic transabdominal rectal resection.Our retrospective study involved a series of 196 rectal cancer patients who underwent laparoscopic transabdominal rectal resection without ileostomy between May 2013 and April 2015 at the Sir Run Run Shaw Hospital, Zhejiang University College of Medicine. The following patient data were collected: demographic data, manifestations of the complication, CRP levels and neutrophil percentage during the first 7 postoperative days.Anastomotic leakage was detected in 11 patients (5.6%). Each group showed significant differences (P < .05) in CRP levels on postoperative days 3 to 7; compared with other groups, the anastomotic leakage group showed significant differences in CRP levels (P < .05) on postoperative day 6. When patients were divided into groups with or without anastomotic leakage, CRP was a reliable predictor on postoperative days 4 to 7 (P < .05, area under the curve > 0.800). The best combination was CRP on postoperative day 6 (area under the curve = 0.932) with a cut-off of 76.6 mg/L, resulting in a sensitivity of 83.3%, a specificity of 94.6% and a negative predictive value of 99%.CRP is a reliable predictor of anastomotic leakage after laparoscopic transabdominal rectal resection surgery. High CRP levels on postoperative days 4 to 7 indicate the need for a more careful patient evaluation.

Predictive and Diagnostic Biomarkers of Anastomotic Leakage: A Precision Medicine Approach for Colorectal Cancer Patients

Development of an anastomotic leak (AL) following intestinal surgery for the treatment of colorectal cancers is a life-threatening complication. Failure of the anastomosis to heal correctly can lead to contamination of the abdomen with intestinal contents and the development of peritonitis. The additional care that these patients require is associated with longer hospitalisation stays and increased economic costs. Patients also have higher morbidity and mortality rates and poorer oncological prognosis. Unfortunately, current practices for AL diagnosis are non-specific, which may delay diagnosis and have a negative impact on patient outcome. To overcome these issues, research is continuing to identify AL diagnostic or predictive biomarkers. In this review, we highlight promising candidate biomarkers including ischaemic metabolites, inflammatory markers and bacteria. Although research has focused on the use of blood or peritoneal fluid samples, we describe the use of implantable medical devices that have been designed to measure biomarkers in peri-anastomotic tissue. Biomarkers that can be used in conjunction with clinical status, routine haematological and biochemical analysis and imaging have the potential to help to deliver a precision medicine package that could significantly enhance a patient's post-operative care and improve outcomes. Although no AL biomarker has yet been validated in large-scale clinical trials, there is confidence that personalised medicine, through biomarker analysis, could be realised for colorectal cancer intestinal resection and anastomosis patients in the years to come.

Computed tomography in suspected anastomotic leakage after colorectal surgery: evaluating mortality rates after false-negative imaging

PURPOSES

We sought to investigate the accuracy of abdominal CT scanning for anastomotic leakage and the effect of false-negative scans on the delay in therapeutic intervention and clinical outcome.

METHOD

Data from a prospectively bi-institutionally maintained database of all patients who underwent elective colorectal surgery with primary anastomosis for malignant or benign disease between 2010 and 2017 were reviewed. Patients with confirmed anastomotic dehiscence at reintervention who underwent a postoperative CT scan for suspected leakage were identified and radiological reports were retrieved.

RESULTS

Seventy-six patients with anastomotic dehiscence were included in the study. American Society of Anesthesiologists score, sex, type of surgical procedure, malignancy, and type of anastomosis do not correlate with postoperative false-negative CT imaging. Postoperative false-negative CT scan, however, led to delayed reintervention (3 vs. 6 h, p = 0.023) and increased mortality (five deaths vs. no deaths, p = 0.043). Free abdominal air (p = 0.001) and extraluminal contrast extravasation (p = 0.001) were found to be predictive of accuracy in anastomotic leakage diagnosis.

CONCLUSION

The suboptimal specificity of a postoperative CT scan in suspected anastomotic leakage after colorectal surgery can delay reintervention and increase mortality.

Radiographic Findings of Anastomotic Leaks

Although computed tomography (CT) scans play an important role in the diagnosis and management of anastomotic leaks (AL), there is no consensus on what radiographic findings are associated with AL. The purpose of this study is to identify the most common CT scan findings associated with AL and whether the amount of extraluminal air or the density of extraluminal fluid can be correlated with the presence of an AL. A retrospective chart review of 210 patients with anastomotic leaks from 2003 to 2010 at Mount Sinai Medical Center was performed. Eighty-six patients fit our criteria and were included. All CT scans were reread by an independent radiologist not involved with patient care. Our study included 59 per cent men and 41 per cent women with a mean age of 51 years. Diagnoses included inflammatory bowel disease (53%), malignancy (21%), and diverticulitis (12%). One hundred per cent of the patients had one of three findings: extraluminal air (92%), extraluminal fluid (88%), or extravasation of contrast (32%). Eighty-one per cent (70/86) had both fluid and air simultaneously. Extraluminal air was seen in 79 patients. The estimated amounts of extraluminal air were as follows: 0 to 25 mL (49%), 26 to 500 mL (41%), 500 to 1000 mL (5%), and more than 1000 mL (5%). The Hounsfield unit (HU) measurements of the fluid ranged from 3 to 633 HUs. The most common CT findings associated with AL are pneumoperitoneum and extraluminal fluid, including extravasation of contrast, which can be seen in up to 100 per cent of patients. The amount of estimated extraluminal air and density of fluid collection have no prognostic value in predicting AL.

Prophylactic intra-abdominal drainage following colorectal anastomoses. A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Clinically evident Anastomotic Leakage (AL) remains one of the most feared complications after colorectal resections with primary anastomosis. The primary aim of this systematic review and meta-analysis was to determine whether Prophylactic Drainage (PD) after colorectal anastomoses confers any advantage in the prevention and management of AL.

METHODS

Systematic literature search was performed using MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE databases for randomized studies comparing clinical outcomes of patients with Drained (D) or Undrained (UD) colorectal anastomoses performed for any cause.

RESULTS

Four randomized controlled trials comparing D and UD patients undergoing colorectal resections with primary anastomosis were included for quantitative synthesis. In total, 1120 patients were allocated to group D (n = 566) or group UD (n = 554). The clinical AL rate was 8.5% in the D group and 7.6% in the UD group, with no statistically significant difference (P = 0.57). Rates of radiological AL (D: 4.2% versus UD: 5.6%; P = 0.42), mortality (D: 3.6% versus UD: 4.4%; P = 0.63), overall morbidity (D: 16.6% versus UD: 18.6%, P = 0.38), wound infection (D: 5.4% versus UD: 5.3%, P = 0.95), pelvic sepsis (D: 9.7% versus UD: 10.5%, P = 0.75), postoperative bowel obstruction (D: 9.9% versus UD: 6.9%, P = 0.07), and reintervention for abdominal complication (D: 9.1% versus UD: 7.9%, P = 0.48) were equivalent between the two groups.

CONCLUSIONS

The present meta-analysis of randomized controlled trials investigating the value of PD following colorectal anastomoses does not support the routine use of prophylactic drains.

The Role of the Radiologist in Determining Disease Severity in Inflammatory Bowel Diseases

Crohn's disease and ulcerative colitis are chronic inflammatory diseases that lead to progressive bowel damage including the development of stricturing and penetrating complications. Increasingly, cross-sectional imaging with computed tomography or magnetic resonance scans have emerged as leading tools to: (1) assess disease activity; (2) monitor response to therapy or disease recurrence; and (3) identify disease-related complications. Several validated radiological scoring systems have been developed to quantify cross-sectional and longitudinal inflammatory burden in these diseases and to monitor response to treatment. Bowel ultrasound is also a simple and inexpensive tool but is operator dependent in its performance.

Colorectal anastomotic leak: delay in reintervention after false-negative computed tomography scan is a reason for concern

BACKGROUND

Early detection of anastomotic leakage (AL) after colorectal surgery followed by timely reintervention is of crucial importance. The aim of this study was to investigate the accuracy of computed tomography (CT) imaging for AL and the effects of delay in reintervention after a false-negative CT.

METHODS

All files from patients who had colorectal surgery with primary anastomoses between 2009 and 2014 were reviewed. The predictive value of CT scanning for AL was determined and correlated with short-term postoperative patient outcomes. In addition, factors predictive of false-negative scans were assessed.

RESULTS

Six hundred and twenty-eight patient files were reviewed. In total, a CT scan was performed in 127 patients. Overall, leakage was seen in 49 patients (7.8%). The positive and negative predictive values were 78 and 88%, respectively. Sensitivity was 73% and specificity 91%. In patients with a true-positive CT (n = 24), reintervention followed after a median interval of 0 days (IQR 1), whereas this was 1 day (IQR 2) in the false-negative group (n = 11) (p < 0.05). This was associated with a significantly increased mortality rate (1/24 = 4.2% vs 5/11 = 45.5%) (p < 0.005), an increased length of hospital stay [median 28 days (IQR 26) vs 54 days (IQR 20) (p < 0.05)].

CONCLUSIONS

Delayed reintervention after false-negative CT scanning is associated with a high mortality rate and a significant increase in length of hospital stay.

Integrated approach to colorectal anastomotic leakage: Communication, infection and healing disturbances

Colorectal anastomotic leakage (CAL) remains a major complication after colorectal surgery. Despite all efforts during the last decades, the incidence of CAL has not decreased. In this review, we summarize the available strategies regarding prevention, prediction and intervention of CAL and categorize them into three categories: communication, infection and healing disturbances. These three major factors actively interact during the onset of CAL. We aim to provide an integrated approach to CAL based on its etiology. The intraoperative air leak test, intraoperative endoscopy, radiological examinations and stoma construction mainly aim to detect and to prevent communication between the intra- and extra-luminal content. Other strategies including postoperative drainage, antibiotics, and infectious-parameter evaluation are intended to detect and prevent anastomotic or peritoneal infection. Most currently available interventions for CAL focus on the control of communication and infection, while strategies targeting the healing disturbances such as lifestyle changes, oxygen therapy and evaluation of metabolic biomarkers still lack wide clinical application. This simplified categorization may contribute to an integrated understanding of CAL. We strongly believe that this integrated approach should be taken into consideration during clinical practice. An integrated approach to CAL could contribute to a better understanding of the etiology of CAL and eventually better patient outcome.

Early Diagnosis of Colonic Anastomotic Leak With Peritoneal Endoscopy

Background and Objectives:

At present, we do not have a reliable method for the early diagnosis of colorectal anastomotic leakage (AL). We tested peritoneal flexible endoscopy through a port placed in the abdominal wall in the early postoperative course, as a new diagnostic method for detection of this complication and evaluated the suggested method for safety, feasibility, and accuracy.

Methods:

Ten swine were randomized into 2 groups: group A, colorectal anastomosis without leakage; and group B, colorectal anastomosis with leakage. A button gastrostomy feeding tube was inserted percutaneously into the peritoneal cavity. Colorectal anastomosis (with or without defect) was created 48 hours after the first operation. The swine were examined by peritoneal flexible endoscopy 8 and 24 hours after the colonic operation, by a consultant surgeon who was blinded to both the presence and the allocated location of the of the anastomotic defect.

Results:

None of the animals showed signs of illness 48 hours after the intraperitoneal gastrostomy tube placement. More than half of the anastomosis circumference was identified in 60 and 10% of the animals at endoscopy 8 and 24 hours, respectively, after the anastomosis was created. Excessive adhesion formation was observed in all animals, irrespective of AL. The sensitivity and specificity of endoscopy in detecting peritonitis 24 hours after AL were both 60%.

Conclusions:

Peritoneal endoscopy is a safe and simple procedure. Visualization of the peritoneal cavity in the early postoperative course was limited due to adhesion formation. Further studies are needed to clarify the accuracy of the procedure and to address additional methodological concerns.

The PRECious trial PREdiction of Complications, a step-up approach, CRP first followed by CT-scan imaging to ensure quality control after major abdominal surgery: study protocol for a stepped-wedge trial

Background

After major abdominal surgery (MAS), 20 % of patients endure major complications, which require invasive treatment and are associated with increased morbidity and mortality. A quality control algorithm after major abdominal surgery aimed at early identification of patients at risk of developing major complications can decrease associated morbidity and mortality. Literature studies show promising results for C-reactive protein (CRP) as an early marker for postoperative complications, however clinical significance has yet to be determined.

Methods

A multicenter, stepped wedge, prospective clinical trial including all adult patients planned to undergo elective MAS. The first period consists of standard postoperative monitoring, which entails on demand additional examinations. This is followed by a period with implementation of postoperative control according to the PRECious protocol, which implicates standardized measurement of CRP levels. If CRP levels exceed 140 mg/L on postoperative day 3,4 or 5, an enhanced CT-scan is performed.

Primary outcome in this study is a combined primary outcome, entailing all morbidity and mortality due to postoperative complications. Complications are graded according to the Clavien-Dindo classification. Secondary outcomes are hospital length of stay, patients reported outcome measures (PROMs) and cost-effectiveness. Data will be collected during admission, three months and one year postoperatively. Approval by the medical ethics committee of the VU University Medical Center was obtained (ID 2015.114).

Discussion

the PRECious trial is a stepped-wedge, multicenter, open label, prospective clinical trial to determine the effect of a standardized postoperative quality control algorithm on postoperative morbidity and mortality, and cost-effectiveness.

Trial registration

www.ClinicalTrials.gov, NCT02102217. Registered 5 February 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-0903-y) contains supplementary material, which is available to authorized users.

Predictive Value of C-Reactive Protein for Major Complications after Major Abdominal Surgery: A Systematic Review and Pooled-Analysis

Background

Early diagnosis and treatment of complications after major abdominal surgery can decrease associated morbidity and mortality. Postoperative CRP levels have shown a strong correlation with complications. Aim of this systematic review and pooled-analysis was to assess postoperative values of CRP as a marker for major complications and construct a prediction model.

Study design

A systematic review was performed for CRP levels as a predictor for complications after major abdominal surgery (MAS). Raw data was obtained from seven studies, including 1427 patients. A logit regression model assessed the probability of major complications as a function of CRP levels on the third postoperative day. Two practical cut-offs are proposed: an optimal cut-off for safe discharge in a fast track protocol and another for early identification of patients with increased risk for major complications.

Results

A prediction model was calculated for major complications as a function of CRP levels on the third postoperative day. Based on the model several cut-offs for CRP are proposed. For instance, a two cut-off system may be applied, consisting of a safe discharge criterion with CRP levels below 75 mg/L, with a negative predictive value of 97.2%. A second cut-off is set at 215 mg/L (probability 20%) and serves as a predictor of complications, indicating additional CT-scan imaging.

Conclusions

The present study provides insight in the interpretation of CRP levels after major abdominal surgery, proposing a prediction model for major complications as a function of CRP on postoperative day 3. Cut-offs for CRP may be implemented for safe early-discharge in a fast-track protocol and, secondly as a threshold for additional examinations, such as CT-scan imaging, even in absence of clinical signs, to confirm or exclude major complications. The prediction model allows for setting a cut-off at the discretion of individual surgeons or surgical departments.

Contrast medium at the site of the anastomosis is crucial in detecting anastomotic leakage with CT imaging after colorectal surgery

PURPOSE

The use of computed tomography (CT) to detect anastomotic leakage (AL) is becoming the standard of care. Accurate detection of AL is crucial. The aim of this study was to define CT criteria that are most predictive for AL.

METHODS

From January 2006 to December 2012, all consecutive patients who had undergone CT imaging because of clinical suspicion of anastomotic leakage after colorectal surgery were analysed. All CT scans were re-evaluated by two independent abdominal radiologists blinded for clinical outcome. The images were scored with a set of criteria and a conclusion whether or not AL was present was drawn. Each separate criterion was analysed for its value in predicting AL by uni- and multivariable logistic regression

RESULTS

Of 668 patients with colorectal surgery, 108 had undergone CT imaging within 16 days postoperatively. According to our standard of reference, 34 (31%) of the patients had AL. Univariable analysis showed that "fluid near anastomosis" (radiologist 1 (rad 1), p < 0.001; radiologist 2 (rad 2), p < 0.001) and "air near anastomosis" (rad 1, p < 0.001; rad 2, p < 0.001), "air intra-abdominally" (rad 1, p = 0.019; rad 2, p = 0.004) and "contrast leakage" (rad 1, p < 0.001; rad 2, p < 0.001) were associated with AL. Contrast leakage was the only independent predictor for AL in multivariable analysis for both radiologists (rad 1, OR 5.43 (95% CI 1.18-25.02); rad 2, OR 8.51 (95% CI 2.21-32.83)).

CONCLUSION

The only independent variable predicting AL is leakage of contrast medium. To improve the accuracy of CT imaging, optimal contrast administration near the anastomosis appears to be crucial.

Anastomotic leakage after colorectal surgery: diagnostic accuracy of CT

OBJECTIVES

To evaluate the diagnostic accuracy of CT in postoperative colorectal anastomotic leakage (AL).

METHODS

Two independent blinded radiologists reviewed 153 CTs performed for suspected AL within 60 days after surgery in 131 consecutive patients, with (n = 58) or without (n = 95) retrograde contrast enema (RCE). Results were compared to original interpretations. The reference standard was reoperation or consensus (a radiologist and a surgeon) regarding clinical, laboratory, radiological, and follow-up data after medical treatment.

RESULTS

AL was confirmed in 34/131 patients. For the two reviewers and original interpretation, sensitivity of CT was 82 %, 87 %, and 71 %, respectively; specificity was 84 %, 84 %, and 92 %. RCE significantly increased the positive predictive value (from 40 % to 88 %, P = 0.0009; 41 % to 92 %, P = 0.0016; and 40 % to 100 %, P = 0.0006). Contrast extravasation was the most sensitive (reviewers, 83 % and 83 %) and specific (97 % and 97 %) sign and was significantly associated with AL by univariate analysis (P < 0.0001 and P < 0.0001). By multivariate analysis with recursive partitioning, CT with RCE was accurate to confirm or rule out AL with contrast extravasation.

CONCLUSIONS

CT with RCE is accurate for diagnosing postoperative colorectal AL. Contrast extravasation is the most reliable sign. RCE should be performed during CT for suspected AL.

KEY POINTS

• CT accurately diagnosed clinically suspected colorectal AL and showed good interobserver agreement • Contrast extravasation was the most sensitive and specific CT sign • Retrograde contrast enema during CT improved positive predictive value • Retrograde contrast enema decreased false-negative or indeterminate original CT interpretations.

Systematic review of preoperative, intraoperative and postoperative risk factors for colorectal anastomotic leaks

BACKGROUND

Anastomotic leak (AL) represents a dreaded complication following colorectal surgery, with a prevalence of 1-19 per cent. There remains a lack of consensus regarding factors that may predispose to AL and the relative risks associated with them. The objective was to perform a systematic review of the literature, focusing on the role of preoperative, intraoperative and postoperative factors in the development of colorectal ALs.

METHODS

A systematic review was performed to identify adjustable and non-adjustable preoperative, intraoperative and postoperative factors in the pathogenesis of AL. Additionally, a severity grading system was proposed to guide treatment.

RESULTS

Of 1707 papers screened, 451 fulfilled the criteria for inclusion in the review. Significant preoperative risk factors were: male sex, American Society of Anesthesiologists fitness grade above II, renal disease, co-morbidity and history of radiotherapy. Tumour-related factors were: distal site, size larger than 3 cm, advanced stage, emergency surgery and metastatic disease. Adjustable risk factors were: smoking, obesity, poor nutrition, alcohol excess, immunosuppressants and bevacizumab. Intraoperative risk factors were: blood loss/transfusion and duration of surgery more than 4 h. Stomas lessen the consequences but not the prevalence of AL. In the postoperative period, CT is the most commonly used imaging tool, with or without rectal contrast, and a C-reactive protein level exceeding 150 mg/l on day 3-5 is the most sensitive biochemical marker. A five-level classification system for AL severity and appropriate management is presented.

CONCLUSION

Specific risk factors and their potential correction or indications for stoma were identified. An AL severity score is proposed to aid clinical decision-making.

CT scan-based modelling of anastomotic leak risk after colorectal surgery

AIM

Prolonged ileus, low-grade fever and abdominal discomfort are common during the first week after colonic resection. Undiagnosed anastomotic leak carries a poor outcome and computed tomography (CT) scan is the best imaging tool for assessing postoperative abdominal complications. We used a CT scan-based model to quantify the risk of anastomotic leak after colorectal surgery.

METHOD

A case-control analysis of 74 patients who underwent clinico-radiological evaluation after colorectal surgery for suspicion of anastomotic leak was undertaken and a multivariable analysis of risk factors for leak was performed. A logistic regression model was used to identify determinant variables and construct a predictive score.

RESULTS

Out of 74 patients with a clinical suspicion of anastomotic leak, 17 (23%) had this complication confirmed following repeat laparotomy. In multivariate analysis, three variables were associated with anastomotic leak: (1) white blood cells count > 9 × 10(9) /l (OR = 14.8); (2) presence of ≥ 500 cm(3) of intra- abdominal fluid (OR = 13.4); and (3) pneumoperitoneum at the site of anastomosis (OR = 9.9). Each of these three parameters contributed one point to the risk score. The observed risk of leak was 0, 6, 31 and 100%, respectively, for patients with scores of 0, 1, 2 and 3. The area under the receiver operating characteristic curve for the score was 0.83 (0.72-0.94).

CONCLUSION

This CT scan-based model seems clinically promising for objective quantification of the risk of a leak after colorectal surgery.

Beware of false-negative CT scan for anastomotic leakage after colonic surgery

BACKGROUND

Anastomotic leakage is one of the most life-threatening complications after colonic surgery. Correct diagnosis and treatment is important to reduce morbidity and mortality. An abdominal CT scan is one of the main diagnostic tools in diagnosing anastomotic leaks. The aim of this study was to examine the accuracy of abdominal CT scanning to detect anastomotic leakage and to evaluate the consequences of a false-negative CT outcome.

METHODS

All consecutive patients who underwent colonic resection for malignant disease between 2009 and 2011 or for benign disease in 2010 were reviewed. Patients in whom a postoperative abdominal CT scan was performed to detect anastomotic leakage were included.

RESULTS

In 97 of 524 patients who underwent colonic surgery, an abdominal CT scan was performed for the suspicion of anastomotic leakage. Overall leakage rate was 10.9 % (n = 57). Mortality rate after leakage was 21.1 % (n = 12). Results from all abdominal CT scans revealed an overall sensitivity of 0.59 (95 % CI 0.43-0.73), a specificity of 0.88 (95 % CI 0.75-0.95), positive predictive value 0.82 (95 % CI 0.64-0.92), negative predictive value 0.70 (95 % CI 0.57-0.81), and an accuracy of 74 %. Delayed reintervention for anastomotic leakage due to a false-negative CT outcome resulted in death in 62.5 % (n = 5).

CONCLUSION

The sensitivity of abdominal CT scanning after colonic surgery is relatively low. A negative CT scan does not rule out anastomotic leakage. Even with a negative CT scan, we should remain equally alert at clinical deterioration as an argument for timely intervention.

Systematic review of methods to predict and detect anastomotic leakage in colorectal surgery

AIM

Anastomotic leakage is a serious complication of gastrointestinal surgery resulting in increased morbidity and mortality, poor function and predisposing to cancer recurrence. Earlier diagnosis and intervention can minimize systemic complications but is hindered by current diagnostic methods that are non-specific and often uninformative. The purpose of this paper is to review current developments in the field and to identify strategies for early detection and treatment of anastomotic leakage.

METHOD

A systematic literature search was performed using the MEDLINE, Embase, PubMed and Cochrane Library databases. Search terms included 'anastomosis' and 'leak' and 'diagnosis' or 'detection' and 'gastrointestinal' or 'colorectal'. Papers concentrating on the diagnosis of gastrointestinal anastomotic leak were identified and further searches were performed by cross-referencing.

RESULTS

Computerized tomography CT scanning and water-soluble contrast studies are the current preferred techniques for diagnosing anastomotic leakage but suffer from variable sensitivity and specificity, have logistical constraints and may delay timely intervention. Intra-operative endoscopy and imaging may offer certain advantages, but the ability to predict anastomotic leakage is unproven. Newer techniques involve measurement of biomarkers for anastomotic leakage and have the potential advantage of providing cheap real-time monitoring for postoperative complications.

CONCLUSION

Current diagnostic tests often fail to diagnose anastomotic leak at an early stage that enables timely intervention and minimizes serious morbidity and mortality. Emerging technologies, based on detection of local biomarkers, have achieved proof of concept status but require further evaluation to determine whether they translate into improved patient outcomes. Further research is needed to address this important, yet relatively unrecognized, area of unmet clinical need.

Risk factors for failure of percutaneous drainage and need for reoperation following symptomatic gastrointestinal anastomotic leak

BACKGROUND

Few studies have evaluated the role of computed tomography-guided percutaneous drainage (PD) in the management of gastrointestinal (GI) anastomotic leaks.

METHODS

Ten-year review of an interventional radiology database identified patients with symptomatic GI anastomotic leaks. Clinical, laboratory, radiographic, and operative characteristics following a technically successful PD which then failed and required reoperation for anastomotic leak were compared with those successfully treated with PD.

RESULTS

Sixty-one patients met study inclusion criteria. Fifty patients (82%) successfully underwent therapeutic PD of a perianastomotic fluid collection, with median follow-up of 16 months. Eleven patients (18%), at a median interval of 16 days, required reoperation following PD. A forward logistic regression showed cardiopulmonary disease (P = .03) and cancer surgery (P = .01) to be factors independently associated with the need for reoperation. The level of the anastomosis, initial fecal diversion/stoma, fluid collection size, and microbiology of aspirate did not predict failure of PD.

CONCLUSIONS

Cardiopulmonary disease and cancer surgery appear to be independent predictors for failure of PD and need for reoperation following a symptomatic GI anastomotic leak.

Polymerase chain reaction for Enterococcus faecalis in drain fluid: the first screening test for symptomatic colorectal anastomotic leakage. The Appeal-study: analysis of parameters predictive for evident anastomotic leakage

PURPOSE

With current diagnostic methods, the majority of patients with symptomatic colorectal anastomotic leakage(CAL) is identified approximately 1 week after operation.The aim of this study is to determine whether real-time polymerase chain reaction (RT-PCR) for detection of Escherichia coli and Enterococcus faecalis on drain fluid can serve as a screening test for CAL in the early postoperative phase.

METHODS

All patients included in this multicenter prospective observational study underwent left-sided colorectal resection for both malignant and benign diseases with construction of an anastomosis. In all patients, an intra-abdominal drain was placed during operation. During the first five postoperative days, drain fluid was processed for RT-PCR. The quantitative results of the RT-PCR on days 2 to 5 were compared to the results of day 1 in order to detect concentration changes.

RESULTS

In total, 243 patients, with both benign and malignant diseases, were included of whom 19 (7.8 %) developed symptomatic CAL. An increase in E. coli concentration was found insignificantly more patients with CAL on day 4 and 5 [p =0.0004; diagnostic odds ratio (DOR) 7.9]. For E. faecalis, this result was found for days 2, 3, and 4 (p <0.003) with highest DOR on day 3 (31.6). Sensitivity and negative predictive values were 92.9 and 98.7 %, respectively, virtually ruling out CAL in case of negative test results on the third postoperative day.

CONCLUSION

Quantitative PCR for E. faecalis performed on drain fluid may be an objective, affordable and fast screening tool for symptomatic colorectal anastomotic leakage.

Imaging techniques for assessment of inflammatory bowel disease: joint ECCO and ESGAR evidence-based consensus guidelines

The management of patients with IBD requires evaluation with objective tools, both at the time of diagnosis and throughout the course of the disease, to determine the location, extension, activity and severity of inflammatory lesions, as well as, the potential existence of complications. Whereas endoscopy is a well-established and uniformly performed diagnostic examination, the implementation of radiologic techniques for assessment of IBD is still heterogeneous; variations in technical aspects and the degrees of experience and preferences exist across countries in Europe. ECCO and ESGAR scientific societies jointly elaborated a consensus to establish standards for imaging in IBD using magnetic resonance imaging, computed tomography, ultrasonography, and including also other radiologic procedures such as conventional radiology or nuclear medicine examinations for different clinical situations that include general principles, upper GI tract, colon and rectum, perineum, liver and biliary tract, emergency situation, and the postoperative setting. The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas such as the comparison of diagnostic accuracy between different techniques, the value for therapeutic monitoring, and the prognostic implications of particular findings.

Systematic review on the value of CT scanning in the diagnosis of anastomotic leakage after colorectal surgery

BACKGROUND

Timely diagnosis of anastomotic leakage after colorectal surgery and adequate treatment is important to reduce morbidity and mortality. Abdominal computed tomography (CT) scanning is the diagnostic tool of preference, but its value may be questionable in the early postoperative period. The accuracy of CT scanning for the detection of anastomotic leakage and its role in timing of intervention was evaluated.

METHODS

A systematic literature search was performed. Relevant publications were identified from four electronic databases between 1990 and 2011. Inclusion criteria were human studies, studies published in English or Dutch, colorectal surgery with primary anastomosis, and abdominal CT scan with reported outcome for the detection of anastomotic leakage. Exclusion criteria were cohort of fewer than five patients, other gastrointestinal surgery, no anastomosis, and radiological imaging other than CT.

RESULTS

Eight studies, including 221 abdominal CT scans, fulfilled the inclusion criteria. Overall, the methodological quality of the studies was poor. The overall sensitivity of CT scanning to diagnose leakage was 0.68 (95 % confidence interval 0.59-0.75) for colonic resection. Data on the sequelae of false-negative CT scanning was not available.

CONCLUSION

There is limited good-quality evidence to determine the value of CT scans in the detection of anastomotic leakage. To prevent delay in diagnosis and appropriate treatment of anastomotic leakage, the relatively low sensitivity of CT scanning must be taken into account.

[Diagnosis and definition of anastomotic leakage from the surgeon's perspective]

The leak rates of different gastrointestinal anastomoses vary considerably but despite this there are common and general concepts for diagnosis and management. Early diagnosis and timely consistent therapy must guide management to prevent harm to the patients. Diagnosis of anastomotic leaks is coupled to clinical signs of the patients and should be initiated promptly. Dependent on the localization of the leak, computed tomography with administration of oral or rectal contrast dye and endoscopy are of high diagnostic value. Both procedures guarantee the option of drainage or stenting through interventional drains or stent placement. Only the implementation of uniform definitions of anastomotic leaks enables surgeons to compare and to improve surgical treatment. Over recent years consensus definitions of postoperative complications including bile leak, pancreatic fistula and colorectal leak have been formulated. These definitions are based on a 3-fold increase of bilirubin (bile leak) or amylase levels (pancreatic fistula) in abdominal drainage fluid compared to serum levels or on an intestinal wall defect with communication of the intraluminal and extraluminal compartments (colorectal anastomosis). The definitions each describe three severity grades A-C. A change of clinical management is required in grade B whereas grade C usually requires a re-operation. Comparable consensus definitions for anastomotic leaks following esophagogastrostomy or esophagojejunostomy or following small bowel anastomosis have not been established. The authors strongly recommend implementation of the presented consensus definitions into clinical and academic daily practice.