Drain fluid biomarkers for the diagnosis of clinically relevant postoperative pancreatic fistula: a diagnostic accuracy systematic review and meta-analysis

BACKGROUND

Pancreatectomy is the only curative treatment available for pancreatic cancer and a necessity for patients with challenging pancreatic pathology. To optimize outcomes, postsurgical complications such as clinically relevant postoperative pancreatic fistula (CR-POPF) should be minimized. Central to this is the ability to predict and diagnose CR-POPF, potentially through drain fluid biomarkers. This study aimed to assess the utility of drain fluid biomarkers for predicting CR-POPF by conducting a diagnostic test accuracy systematic review and meta-analysis.

METHODS

Five databases were searched for relevant and original papers published from January 2000 to December 2021, with citation chaining capturing additional studies. The QUADAS-2 tool was used to assess the risk of bias and concerns regarding applicability of the selected studies.

RESULTS

Seventy-eight papers were included in the meta-analysis, encompassing six drain biomarkers and 30 758 patients with a CR-POPF prevalence of 17.42%. The pooled sensitivity and specificity for 15 cut-offs were determined. Potential triage tests (negative predictive value >90%) were identified for the ruling out of CR-POPF and included postoperative day 1 (POD1) drain amylase in pancreatoduodenectomy (PD) patients (300 U/l) and in mixed surgical cohorts (2500 U/l), POD3 drain amylase in PD patients (1000-1010 U/l) and drain lipase in mixed surgery groups (180 U/l). Notably, drain POD3 lipase had a higher sensitivity than POD3 amylase, while POD3 amylase had a higher specificity than POD1.

CONCLUSIONS

The current findings using the pooled cut-offs will offer options for clinicians seeking to identify patients for quicker recovery. Improving the reporting of future diagnostic test studies will further clarify the diagnostic utility of drain fluid biomarkers, facilitating their inclusion in multivariable risk-stratification models and the improvement of pancreatectomy outcomes.

CRP in Drain Fluid as a Predictive Marker of Anastomotic Leak in Colorectal Surgery: A Systematic Review of the Literature

BACKGROUND/AIM

Anastomotic leak (AL) remains one of the most troublesome complications in general surgery. The current review aimed to assess the level of C-reactive protein (CRP) in drainage fluid after entero-enteric, colonic, or colorectal anastomosis as a predictive biomarker for AL.

MATERIALS AND METHODS

Four medical databases (PUBMED-MEDLINE, Google Scholar, UpToDate, and Cochrane Library) were searched in January 2023 for prospective or retrospective studies on the role of acute-phase proteins in drainage fluid as a predictive biomarker of AL. Two independent researchers gathered and processed the data using MedCalc. The data were pooled and Student's t-test was used to compare the data between the AL and non-AL groups.

RESULTS

Overall, four studies were included in the current review, containing 753 patients in total, for whom various types of enteric and colonic anastomoses were constructed. Overall 79 (10.49%) of patients demonstrated AL and the mean CRP level (±standard deviation) on postoperative day 3 was 167.7±77.13 mg/l. On the contrary, the non-AL group (674/753) had a statistically significantly lower mean CRP level at 83.76±20.32 mg/l. CRP values were not related to mortality. It was not possible to propose a CRP cut-off indicating an increased risk for AL as the data were insufficient.

CONCLUSION

The CRP level in drainage fluid might be a valuable biomarker for predicting the possibility of AL in general surgery. However, further and larger-scale studies are needed to establish a CRP cut-off value and this variable would possibly be different for patients with different pathologies.

Drain fluid amylase as a biomarker for the detection of anastomotic leakage after rectal resection without a diverting ileostomy

BACKGROUND

Anastomotic leak (AL) is the anathema of colorectal surgery. Early diagnosis is an essential segue to early intervention. A temporary diverting ileostomy (TDI) does not prevent an AL and presents inherent complications of its own. Numerous drain fluid biomarkers (BM) have been studied in colorectal surgery and extravasated intraluminal substances (EILS) such as amylase have shown promise. The aim of this study was to assess drain fluid amylase (DFA) as a BM of AL after minimally invasive rectal resection without a TDI.

METHODS

A single centre prospective cohort study performed from 2018 to 2021. The primary outcome was DFA measured daily whilst the drain was in situ. Rectal tube amylase was also measured for the first two post-operative days to quantitate the intra-luminal levels of the enzyme. DFA was compared between patients who experienced AL and those who did not.

RESULTS

Of the 62 patients studied, six (9.7%) experienced AL. There was a statistically significant difference in DFA between patients who experienced AL (Median:1373.5 U/L; IQR: 306-7953) and patients who did not experience an AL (Median: 27.0 U/L; IQR: 16-38); p < 0.0001.

CONCLUSIONS

The measurement of drain fluid amylase is a highly sensitive BM of early clinical anastomotic leak in patients undergoing a rectal resection with an extraperitoneal anastomosis and when a TDI is not incorporated. This simple, inexpensive and non-invasive test should be considered in all patients as an adjunct to the clinical diagnosis and differentiation of AL from other postoperative complications.

An umbrella systematic review of drain fluid analysis in colorectal surgery for the detection of anastomotic leak: Not yet ready to translate research studies into clinical practice

AIM

Anastomotic leak (AL) is the most important complication of intestinal surgery with an anastomosis. Whilst a number of studies have defined risk factors for AL, frustratingly, low-risk patients still develop AL. Studies have looked at drain fluid analysis for detection of AL, but these findings have failed to translate into routine clinical practice. This umbrella systematic review aims to provide an overview of the promising candidate biomarkers (BMs) that show potential to translate into clinical practice.

METHODS

A systematic literature search was conducted in MEDLINE, EMBASE, and the Cochrane, KSR Evidence and the Epistemonikos databases on the 14 April 2021. Only systematic reviews of cohort or controlled studies measuring drain fluid biomarkers in humans were included. The methodological quality of the reviews was assessed using the AMSTAR 2 instrument. Clinical trial registries were searched for trials actively investigating drain fluid BMs. Candidate BMs were classified, and threshold values investigated.

RESULTS

Nine systematic reviews, published between 2007 and 2020, met the inclusion criteria, and contained a total of 36 cohort studies. A total of 38 different BMs were studied. The most promising category of drain fluid BM was the extravasated intra-luminal substances (EILS) and five registered trials of these BMs were found. Two of nine reviews were of moderate quality.

CONCLUSIONS

The majority of BMs show inconsistent threshold values and are in the experimental stage. A number are not readily available for adoption into routine clinical practice. Most do not state a cut-off value to be considered as diagnostic.

A multicentre cohort study of serum and peritoneal biomarkers to predict anastomotic leakage after rectal cancer resection

AIM

Anastomotic leakage (AL) is one of the most feared complications after rectal resection. This study aimed to assess a combination of biomarkers for early detection of AL after rectal cancer resection.

METHOD

This study was an international multicentre prospective cohort study. All patients received a pelvic drain after rectal cancer resection. On the first three postoperative days drain fluid was collected daily and C-reactive protein (CRP) was measured. Matrix metalloproteinase-2 (MMP2), MMP9, glucose, lactate, interleukin 1-beta (IL1β), IL6, IL10, tumour necrosis factor alpha (TNFα), Escherichia coli, Enterococcus faecalis, lipopolysaccharide-binding protein and amylase were measured in the drain fluid. Prediction models for AL were built for each postoperative day using multivariate penalized logistic regression. Model performance was estimated by the c-index for discrimination. The model with the best performance was visualized with a nomogram and calibration was plotted.

RESULTS

A total of 292 patients were analysed; 38 (13.0%) patients suffered from AL, with a median interval to diagnosis of 6.0 (interquartile ratio 4.0-14.8) days. AL occurred less often after partial than after total mesorectal excision (4.9% vs 15.2%, P = 0.035). Of all patients with AL, 26 (68.4%) required reoperation. AL was more often treated by reoperation in patients without a diverting ileostomy (18/20 vs 8/18, P = 0.03). The prediction model for postoperative day 1 included MMP9, TNFα, diverting ileostomy and surgical technique (c-index = 0.71). The prediction model for postoperative day 2 only included CRP (c-index = 0.69). The prediction model for postoperative day 3 included CRP and MMP9 and obtained the best model performance (c-index = 0.78).

CONCLUSION

The combination of serum CRP and peritoneal MMP9 may be useful for earlier prediction of AL after rectal cancer resection. In clinical practice, this combination of biomarkers should be interpreted in the clinical context as with any other diagnostic tool.

Persisting ratio of total amylase output in drain fluid can predict postoperative clinical pancreatic fistula

BACKGROUND/PURPOSE

A consistent predictor for pancreatic fistula (PF) development in the early period after pancreatic resection is still lacking.

PATIENTS AND METHODS

A total of 54 consecutive patients undergoing pancreatic resection were enrolled between June 2007 and April 2010. Pancreaticoduodenectomy (PD) and distal pancreatectomy (DP) were performed in 38 and 16 patients, respectively. For the purpose of finding an early predictor for PF development, we investigated drain amylase levels (d-Amy, IU/mL), drain output volume (d-Vol, mL/day) and drain amylase output (Amy-V, IU/day) on postoperative days (POD) 1 and 3. Amy-V was calculated as the product of d-Amy and d-Vol, and was expressed as the sum of values obtained from all drains. In addition, the ratio of d-Amy or Amy-V on POD3 to that on POD1 was calculated as the persisting ratio in each patient.

RESULTS

The overall incidence of clinical PF (International Study Group on Pancreatic Fistula Grade B and C) was 16.7%, occurring in 13.1% after PD and 25% after DP. All PF occurred in cases with a remnant pancreas of soft texture. There was no significant difference in d-Amy, d-Vol, or Amy-V on POD1 and POD3 between patients with and without clinical PF. The persisting ratio of Amy-V was significantly lower in patients without clinical PF compared to those with clinical PF (p = 0.029). Furthermore, the persisting ratio of Amy-V was significantly lower in patients with Grade A PF compared to those with Grade B PF (p = 0.03).

CONCLUSION

The persisting ratio of drain amylase output is a new significant predictive factor for clinical PF development.

Peritoneal fluid cytokines and matrix metalloproteinases as early markers of anastomotic leakage in colorectal anastomosis: a literature review and meta-analysis

AIM

There has been recent interest in the measurement of peritoneal fluid cytokines in the early postoperative period to help diagnose anastomotic leakage at a preclinical stage. The currently available literature on the early diagnosis of colorectal anastomotic leakage by estimation of drain fluid cytokines or matrix metalloproteinases (MMP) is reviewed.

METHOD

A literature search was performed in PubMed, EMBASE and the Cochrane library for all publications studying the feasibility of diagnosing colorectal anastomotic leakage earlier by estimation of peritoneal fluid cytokine or MMP levels. A meta-analysis of the most commonly measured cytokines was performed.

RESULTS

Eight publications were included. Tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were most frequently studied. Most studies found significantly higher levels of TNF-α and IL-6 in patients with anastomotic leakage during the first three postoperative days. In the meta-analysis IL-6 levels were significantly higher from day 1 and TNF-α from day 2. MMP-9 was most often significantly elevated in patients with anastomotic leakage.

CONCLUSION

Measurement of drain fluid cytokines and MMP has the potential to diagnose colorectal anastomotic leakage at a preclinical stage, but is not yet ready for clinical use. Further research is needed, possibly using IL-6 in combination with other cytokines and MMP as markers.