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

Colorectal anastomotic leakage: a narrative review of definitions, grading systems, and consequences of leaks

Background

Anastomotic leaks (ALs) are a significant and feared postoperative complication, with incidence of up to 30% despite advances in surgical techniques. With implications such as additional interventions, prolonged hospital stays, and hospital readmission, ALs have important impacts at the level of individual patients and healthcare providers, as well as healthcare systems as a whole. Challenges in developing unified definitions and grading systems for leaks have proved problematic, despite acknowledgement that colorectal AL is a critical issue in intestinal surgery with serious consequences. The aim of this study was to construct a narrative review of literature surrounding definitions and grading systems for ALs, and consequences of this postoperative complication.

Methods

A literature review was conducted by examining databases including PubMed, Web of Science, OVID Embase, Google Scholar, and Cochrane library databases. Searches were performed with the following keywords: anastomosis, anastomotic leak, colorectal, surgery, grading system, complications, risk factors, and consequences. Publications that were retrieved underwent further assessment to ensure other relevant publications were identified and included.

Results

A universally accepted definition and grading system for ALs continues to be lacking, leading to variability in reported incidence in the literature. Additional factors add to variability in estimates, including differences in the anastomotic site and institutional/individual differences in operative technique. Various groups have worked to publish guidelines for defining and grading AL, with the International Study Group of Rectal Cancer (ISGRC/ISREC) definition the current most recommended universal definition for colorectal AL. The burden of AL on patients, healthcare providers, and hospitals is well documented in evidence from leak consequences, such as increased morbidity and mortality, higher reoperation rates, and increased readmission rates, among others.

Conclusions

Colorectal AL remains a significant challenge in intestinal surgery, despite medical advancements. Understanding the progress made in defining and grading leaks, as well as the range of negative outcomes that arise from AL, is crucial in improving patient care, reduce surgical mortality, and drive further advancements in earlier detection and treatment of AL.

Drainage fluid LDH and neutrophil to lymphocyte ratio as biomarkers for early detecting anastomotic leakage in patients undergoing colorectal surgery

OBJECTIVES

In this study, we investigated the role of several circulating and drainage fluid biomarkers for detecting postoperative complications (PCs) and anastomotic leakage (AL) in patients undergoing colorectal surgery.

METHODS

All consecutive patients undergoing colorectal surgery between June 2018 and April 2020 were prospectively considered. On postoperative days (POD) 1, 3, and 5, we measured lactate dehydrogenase (LDH) in drainage fluid, C-reactive protein (CRP) in serum and drainage fluid, and neutrophil to lymphocyte ratio (NLR).

RESULTS

We enrolled 187 patients. POD1 patients with AL had higher serum CRP levels, while on POD3 and on POD5 higher NLR and serum CRP. LDH and CRP in drainage fluid were also significantly higher at both time points. The area under the curves (AUCs) of serum and drainage fluid CRP were 0.752 (0.629-0.875) and 0.752 (0.565-0.939), respectively. The best cut-off for serum and drainage fluid CRP was 185.23 and 76 mg/dL, respectively. The AUC of NLR on POD3 was 0.762 (0.662-0.882) with a sensitivity and specificity of 84 and 63 %, respectively, at a cut-off of 6,6. Finally, drainage fluid LDH showed the best diagnostic performance for AL, with an AUC, sensitivity, and specificity of 0.921 (0.849-0.993), 82 %, and 90 % at a cut-off of 2,186 U/L. Trends in serum parameters between patients with or without PCs or AL were also evaluated. Interestingly, we found that NLR decreased faster in patients without PCs than in patients with PCs and patients with AL.

CONCLUSIONS

Drainage fluid LDH and NLR could be promising biomarkers of PCs and AL.

Development and Validation of a Novel Nomogram Model for Early Diagnosis of Anastomotic Leakage After Laparoscopic Colorectal Cancer Surgery

Background: This study aimed to investigate the clinical value of inflammatory factors for predicting anastomotic leakage (AL) after laparoscopic colorectal cancer surgery and establish a nomogram model to assess the probability of its occurrence. Patients and Methods: Data of 637 patients who underwent laparoscopic colorectal cancer surgery between June 2019 and June 2022 were collected. Differences in procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) levels before surgery and on postoperative day (POD) 3 and 5 were compared between patients with and without AL (AL and non-AL groups, respectively). The diagnostic accuracy was determined using the area under the receiver operating characteristic curve (AUC), and a nomogram model was developed. Results: Post-operative AL occurred in 46 (7.2%) patients. Procalcitonin, CRP, and WBC levels on POD 3 and 5 were higher in the AL group than in the non-AL group. The AUCs of PCT, CRP, and WBC levels for predicting AL on POD 3 were 0.833, 0.757, and 0.756, respectively, which were better than those on POD 5 (AUC = 0.669, 0.581, and 0.588, respectively). The nomogram model for AL was developed based on five variables (PCT, CRP, WBC, American Society of Anesthesiologists [ASA] grade and comorbidities), and it had an AUC of 0.922. Calibration curves demonstrated that the nomogram had good fit. The Delong test showed that the AUC of the nomogram for predicting the probability of AL was higher than that of PCT alone (z = 2.311, p = 0.02). Conclusions: Procalcitonin measured on POD 3 seems to be a promising negative predictor of AL after laparoscopic colorectal cancer surgery. Furthermore, the nomogram model developed in our study, which utilizes a series of predictors that can be easily accessed, has demonstrated potential to further improve the prediction accuracy.

A Miraculous Save: Gangrenous Bowel and Meckle's Diverticulum With Acute Superior Mesenteric Artery Thrombosis

The superior mesenteric artery (SMA) is vital for parts of the small intestine and ascending colon. Thrombosis of this major artery is a severe and potentially fatal condition involving the occlusion of the arterial vascular supply, causing ischemia predisposing to gangrene. Meckel's diverticulum is a congenital outpouching in the lower part of the small intestine. The condition of gangrenous meckels diverticulum is, therefore, even more limited. This study presents a unique case of a 45-year-old male with coexisting features of SMA thrombus with acute small bowel intestinal obstruction. During the study, the patient was found to have sickle cell anemia with an AS pattern, which may have predisposed the formation of a thrombus. The patient underwent sequential management of active thrombus by thrombolysis first, followed by resection anastomosis for gangrenous bowel. With precise monitoring and therapeutic care, the patient made a remarkable recovery. The condition possesses a high mortality rate. Prompt recognition and timely intervention in this case are of utmost significance.

Promoting wound recovery through stable intestinal flora: Reducing post-operative complications in colorectal cancer surgery patients

In recent years, the relationship between intestinal flora and post-operative recovery, particularly in colorectal cancer (CRC) surgery patients, it has been hypothesized that intestinal flora stability influences wound healing, reduces complications and improves overall recovery outcomes after surgical interventions. This study examined the relationship between intestinal flora stability and post-operative recovery in patients undergoing CRC surgery. Between May 2020 and 2023, 80 CRC patients from our hospital's Colorectal Surgery Department were enrolled. A random number table was used to divide them into two categories. Both groups were subjected to distinct gastrointestinal preparation protocols. Indicators of clinical therapeutic effect, intestinal flora balance following surgery, post-operative complications and quality of life were evaluated. The observation group, which adhered to a distinct gastrointestinal regimen, demonstrated a statistically significant improvement in post-operative outcomes, with a clinical effectiveness rate of 97.5% compared to the control group's 75%. In addition, the observation group had a lower incidence of intestinal flora imbalance following surgery than the control group. The observation group had lower incidences of intestinal obstruction, infection, anastomotic leakage, incisional tumour implantation and delayed diarrhoea. Using the KPS score and the BMI, post-treatment assessments of the observation group's quality of life revealed significant enhancements in comparison to the control group. Additionally, wound healing rates were superior in the observation group, with a correlation between stable intestinal flora and decreased wound infection rates. The type of post-operative diet influenced the stabilization of the gut flora, with a high-fibre diet producing superior results in both groups. The stability of intestinal flora influences the post-operative rehabilitation of patients undergoing CRC surgery favourably. Appropriate bowel preparation and dietary considerations can reduce post-operative complications, improve wound healing rates and enhance overall quality of life.

Routine Endoscopy Prior to Surgical Ostomy Closure: An Obsolete Concept

BACKGROUND

Closure of temporary diverting ostomies is commonly preceded by an endoscopic study of the colonic mucosa and anastomosis, despite lacking evidence of its relevance and impact on subsequent operative management.

AIM

We sought to determine the incidence of pathological findings and therefore evaluate the clinical benefit of routine pre-operative endoscopy in asymptomatic patients, hypothesizing sole evaluation of the anastomotic integrity to be sufficient in these cases.

METHODS

We retrospectively identified all adult patients with ostomy installations who were followed up for potential reversal surgery between 2002 and 2020 at the University Hospital of Zurich, Switzerland. Main outcome measures were the incidence of endoscopically identified pathological findings in the asymptomatic case cohort and their impact on the subsequent course of treatment.

RESULTS

Pre-procedural endoscopic data of 187 cases evaluated for ostomy closure were evaluated. Relevant mucosal findings in the asymptomatic cohort were documented in 26.3% and findings at the anastomotic site detected in 8.7%. A change in subsequent surgical management was noted in 10 patients of the entire cohort (5.3%) and in 9 (5.1%) of all asymptomatic cases. Upon multivariate analyses, the age range of 51 to 60 years old was found to be significantly linked to the presence of endoscopic findings entailing a change in patient management.

CONCLUSION

Our findings strongly suggest ostomy closure surgery without previous assessment of the bowel mucosa by means of endoscopy to be acceptable in asymptomatic patients. However, we found it to be indicated in all patients meeting the screening criteria for colorectal carcinoma.

Continuous pH monitoring using a sensor for the early detection of anastomotic leaks

Anastomotic leaks (AL) and staple line leaks are a serious post-operative complication that can develop following bariatric surgery. The delay in the onset of symptoms following a leak usually results in reactive diagnostics and treatment, leading to increased patient morbidity and mortality, and a clinical and economic burden on both the patient and the hospital. Despite support in literature for pH as a biomarker for early detection of AL, the current methods of pH detection require significant clinician involvement and resources. Presented here is a polyaniline (PANI)-based pH sensor that can be connected inline to surgical drains to continuously monitor peritoneal secretion in real time for homeostatic changes in pH. During this study, the baseline peritoneal fluid pH was measured in two pigs using the PANI sensor and verified using a benchtop pH probe. The PANI sensor was then utilized to continuously monitor the changes in the pH of peritoneal effluent, as a gastric leak was simulated. The inline sensors were able to detect the resulting local changes in drainage pH within 10 min of leak induction. The successful implementation of this sensor in clinical practice can both enable high efficiency continuous monitoring of patient status and drastically decrease the time required to detect AL, thus potentially decreasing the clinical and economic burden incurred by gastric leaks.

Predictive Factors for Anastomotic Leakage Following Colorectal Cancer Surgery: Where Are We and Where Are We Going?

Anastomotic leakage (AL) remains one of the most severe complications following colorectal cancer (CRC) surgery. Indeed, leaks that may occur after any type of intestinal anastomosis are commonly associated with a higher reoperation rate and an increased risk of postoperative morbidity and mortality. At first, our review aims to identify specific preoperative, intraoperative and perioperative factors that eventually lead to the development of anastomotic dehiscence based on the current literature. We will also investigate the role of several biomarkers in predicting the presence of ALs following colorectal surgery. Despite significant improvements in perioperative care, advances in surgical techniques, and a high index of suspicion of this complication, the incidence of AL remained stable during the last decades. Thus, gaining a better knowledge of the risk factors that influence the AL rates may help identify high-risk surgical patients requiring more intensive perioperative surveillance. Furthermore, prompt diagnosis of this severe complication may help improve patient survival. To date, several studies have identified predictive biomarkers of ALs, which are most commonly associated with the inflammatory response to colorectal surgery. Interestingly, early diagnosis and evaluation of the severity of this complication may offer a significant opportunity to guide clinical judgement and decision-making.

Proteína C reactiva como biomarcador predictivo de fuga anastomótica en cirugía oncológica colorrectal: estudio de cohorte retrospectivo

Introducción. La fuga anastomótica es la complicación más grave del tratamiento quirúrgico del cáncer de colon por su alta morbimortalidad. El diagnóstico evidente, manifestado por la salida de contenido intestinal por drenajes o la herida quirúrgica, ocurre tardíamente (entre el 6º y 8º día). El objetivo de este trabajo fue estudiar la variación de los valores de la proteína C reactiva postoperatoria para hacer un diagnóstico precoz. Métodos. Estudio observacional, analítico, retrospectivo, de una cohorte de pacientes con neoplasia, en quienes se realizó cirugía oncológica con anastomosis intestinal, entre enero de 2019 y diciembre de 2021. Se midieron los valores en sangre de proteína C reactiva postoperatoria (1°, 3° y 5° días). Resultados. Se compararon 225 casos operados que no presentaron fuga con 45 casos con fuga. En los casos sin fuga, el valor de proteína C reactiva al 3º día fue de 148 mg/l y al 5º día de 71 mg/l, mientras en los casos con fuga, los valores fueron de 228,24 mg/l y 228,04 mg/l, respectivamente (p<0,05). Para un valor de 197 mg/l al 3º día la sensibilidad fue de 77 % y para un valor de 120 mg/l al 5º día la sensibilidad fue de 84 %. Conclusión. El mejor resultado de proteína C reactiva postoperatoria para detectar precozmente la fuga anastomótica se observó al 5º día. El valor de 127 mg/l tuvo la mejor sensibilidad, especificidad y valor predictivo negativo, lo cual permitiría el diagnóstico temprano y manejo oportuno de esta complicación.

Distinctive characteristics of granulation tissue in laparotomy wounds with underlying oncological processes

This study aimed to investigate the effects of malignant neoplasms on the morphological characteristics of laparotomy wound granulation tissue in the muscular-aponeurotic layer. The study involved a sample of 34 deceased individuals who had undergone abdominal organ surgery. Biopsy samples were taken from the muscular-aponeurotic layer of the anterior abdominal wall and subjected to histological examination, including staining with hematoxylin and eosin and methylene blue/Chromotrope 2B using N.Z. Slinchenko's method. Descriptive methods and morphometry were used to evaluate pathomorphological changes. The results suggest that malignant neoplasms significantly impede and decelerate the maturation of laparotomy wound granulation tissue. Surgeries performed at the late stages of abdominal organ malignant neoplasms result in an uneven and slow maturation of the tissue, characterized by a higher prevalence of lymphoid cells, increased blood vessel volume, reduced optical density of stained collagen fibers, and pronounced chromotropophilia of collagen fibers. These distinct features should be considered to prevent postoperative eventration, a complication that is more likely to occur in this patient group. Clinicians should be aware of the possible consequences of malignant neoplasms on laparotomy wound granulation tissue, which may require additional measures to prevent postoperative complications in these patients.

Early and late anastomotic leak after colorectal surgery: A systematic review of the literature

The aim of this study was to review and to assess the quality of the scientific articles regarding early and late anastomotic leak (AL) after colorectal surgery and their risk factors. An electronic systematic search for articles on Colorectal Surgery, AL and its timing was undertaken using the MEDLINE database via PubMed, Cochrane and Embase. The selected articles were thoroughly reviewed and assessed for methodological quality using a validated methodology quality score (MINCIR score). This review was registered in the PROSPERO registry under ID: CRD42022303012. 9 articles were finally reviewed in relation to the topic of early and late anastomotic leak. There is a lack of consensus regarding the exact cut-off in time to define early and late anastomotic leak, but it is clear that they are two differentiated entities. The first, occurring in relation to technical factors; whereas the latter, is related to impaired healing.

The Significance of Blood and Peritoneal Fluid Biochemical Markers in Identifying Early Anastomotic Leak following Colorectal Resection-Findings from a Single-Center Study

Background and Objectives: The aim of our study was to evaluate the value of leukocyte, C reactive protein (CRP), procalcitonin, lactate, and carcinoembryonic antigen (CEA) in blood and peritoneal fluid in early recognition of anastomotic leak (AL) after colorectal resections. Materials and Methods: Our pilot prospective cohort study was conducted at the abdominal surgery department at University Medical Center Ljubljana. A total of 43 patients who underwent open or laparoscopic colorectal resection because of benign or malignant etiology were enrolled. All of the patients had primary anastomosis without stoma formation. Results: Three patients in our patient group developed AL (7%). We found a statistically significant elevation of serum lactate levels in patients that developed AL compared to those who did not but noted no statistically relevant difference in the blood or peritoneal fluid levels of other biochemical markers. Conclusions: Elevated lactate levels may be considered a promising biomarker for the early diagnosis of AL, but more research on bigger patient groups is warranted.

Predictors That Identify Complications Such As Anastomotic Leak in Colorectal Surgery: A Systematic Review

Leakage of the anastomotic site is considered to be one of the most serious complications after colon and rectal surgery. It is associated with increased mortality, morbidity, and longer hospital stays. This systematic review examines the need for blood markers such as C-reactive protein (CRP), procalcitonin (PCT), albumin, and various other molecular markers that assist in their propensity to diagnose anastomotic leakage (AL) early after surgery.

Utilizing PubMed and Google Scholar as resources and including the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for the articles, and studies over the last five years were included. A total of 12 studies have been discussed, and most articles suggest CRP as an excellent indicator. CRP compared to Dutch leakage scores (DLS) and PCT studies suggest that the three combinations improve the predictable outcome of AL. In addition, CRP and PCT have been shown to diagnose AL early in the postoperative period. Other studies include the role of markers of oxidative stress markers, Interleukin-6, Interleukin-10, and other molecular markers in the peritoneal drain which are predictive for identifying AL after three days postoperatively (POD-3).

Overall, CRP has proven to be a reliable standard indicator of diagnosis. This is because the postoperative elevation of this protein indicates a problem of leakage with clinical symptoms. Other blood parameters are useful for diagnosis as well, but the limitations are the lack of appropriate studies and the number of randomized controlled trials in this area of ​​study.

Evaluation of the Use of Inflammatory Biomarkers in the Early Detection of Anastomotic Leakage after Oesophagectomy

Background

Postoperative anastomotic leakage remains a major complication of esophagectomy. The development of a reliable method of early detection of anastomotic leakage can revolutionize the management of esophageal carcinoma.

Materials and Methods

This is a retrospective data analysis of 147 patients who underwent Ivor–Lewis esophagectomy as a curative attempt to treat distal esophageal carcinoma in our surgery department between 2010 and 2021. C-reactive protein and white blood cell count in postoperative days 1, 3, 5, and 8 were compared in patients with and without anastomotic leakage. The diagnostic accuracy of these tests was challenged against the clinical reference standard represented by computed tomography or upper gastrointestinal endoscopy.

Results

Twenty-eight patients (19%) developed anastomotic leakage. C-reactive protein values in postoperative day 8 were the only parameter to qualify as a potential clinically helpful test with an area under the receiver operating curve of 0.85 and a P value of less than .01. We calculated the cutoff value for C-reactive protein during postoperative day 8 to be 10.85 mg/dL with specificity and sensitivity of 73.1% and 89.3%, respectively. C-reactive protein showed a positive predictive value of 43.9% and a negative predictive value of 96.7% at this cutoff value.

Conclusion

An absolute diagnostic value of postoperative estimation of serum inflammatory biomarkers to detect anastomotic leakage could not be proved. Serum C-reactive protein on postoperative day 8 with a cutoff value of 10.85 mg/dL could be used to exclude anastomotic leakage after esophagectomy to serve as one of the discharge criteria of the patients.

•

Anastomotic leakage is a serious and quite common complication after esophagectomy.

•

Early detection of anastomotic leakage is crucial to successful management.

•

Increased inflammatory biomarkers suggest the presence of anastomotic leakage.

•

Increased serum C-reactive protein is a potential detector of anastomotic leakage.

Peritoneal Cytokines as Early Biomarkers of Colorectal Anastomotic Leakage Following Surgery for Colorectal Cancer: A Meta-Analysis

Background

Postoperative colorectal anastomotic leakage (CAL) is a devastating complication following colorectal resection. However, the diagnosis of anastomotic leakage is often delayed because the current methods of identification are unable to achieve 100% clinical sensitivity and specificity. This meta-analysis aimed to evaluate the predictive value of peritoneal fluid cytokines in the detection of CAL following colorectal surgery.

Methods

A comprehensive search was conducted on PubMed, Embase, Cochrane Library, and Web of Science before June 2021 to retrieve studies regarding peritoneal fluid cytokines as early markers of CAL. Pooled analyses of interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor (TNF) were performed. The means (MD) and standard deviations (SD) of the peritoneal fluid cytokines were extracted from the included studies. Review Manager Software 5.3 was used for data analysis.

Results

We included eight studies with 580 patients, among which 85 (14.7%) and 522 (44.5%) were evaluated as the CAL and non-CAL groups, respectively. Compared to the non-CAL group, the CAL group had significantly higher peritoneal IL-6 levels on postoperative day (POD) 1–3 (P = 0.0006, 0.0002, and 0.002, respectively) and slightly higher TNF levels on POD 4 (P = 0.0002). Peritoneal levels of IL-1β and IL-10 were not significantly different between the two groups in this study.

Conclusion

Peritoneal IL-6 levels can be a diagnostic marker for CAL following colorectal surgery, whereas the value of TNF needs further exploration in the future.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/#myprospero], PROSPERO (CRD42021274973)

Intraoperative Control of Hemoglobin Oxygen Saturation in the Intestinal Wall during Anastomosis Surgery

During surgery for colon cancer, monitoring of the oxygen saturation of hemoglobin in the tissues under study makes it possible to assess the degree of blood supply to the anastomosis areas of the colon. Adequate blood supply in this area is decisive in terms of the consistency of the anastomosis and can significantly reduce the risk leakage of anastomosis. In this work, we propose a new approach to assessing the hemoglobin oxygen saturation based on measuring both the diffuse reflectance and transmittance spectra of the colon wall tissues. The proposed method is based on the use of two fiber-optic tools for irradiation from both sides—the intestinal lumen and the outside of the intestinal wall. The spectra are recorded from the external side. To determine the degree of hemoglobin saturation, two algorithms, both based on the Taylor series expansion of the coefficient of light attenuation by tissues, are proposed. The results of a clinical study of the proposed approach on volunteers were obtained, allowing to draw a conclusion about the applicability of the approach in a clinical setting.