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

Drain fluid iodine as a biomarker of anastomotic leak after low anterior resection in patients undergoing Gastrografin rectal tube flushes and omission of a diverting ileostomy: The GUSH study

AIM

Anastomotic leak (AL) is the anathema of colorectal surgery and its occurrence constitutes a serious risk to patients and places a substantial burden on the health system. The analysis of extravasated intraluminal substances in drain fluid has shown promise for the early detection of AL. The aim of this study is to assess the measurement of drain fluid iodine as a biomarker of AL.

METHOD

This prospective, observational, 2b exploration cohort study measured the iodine in drain fluid of patients undergoing a low colorectal anastomosis and without a diverting ileostomy (DI) when the rectal tube was flushed with Gastrografin®. Iodine was measured by dual-energy computed tomography (DECT) and inductively coupled plasma mass spectroscopy (ICPMS).

RESULTS

Sixty-six patients underwent a rectal resection and low colorectal anastomosis. Five patients experienced an AL. Four had grade C AL and returned to the operating theatre for peritoneal lavage and DI. The fifth was diagnosed at 30 days postoperatively and underwent image-guided drainage (grade B). The mean drain fluid iodine was significantly elevated in patients who experienced an AL compared with those who did not, as measured by DECT and ICPMS. The mean iodine value was 6.05 mg/mL vs. 0.088 mg/mL (p < 0.0001) for DECT and 41 437 μmol/L vs. 3.81 μmol/L (p < 0.0001) for ICPMS.

CONCLUSION

This study showed that drain iodine can be used as a sensitive indicator of early AL in patients undergoing a rectal resection with an extraperitoneal colorectal anastomosis and omission of a DI and when the rectal tube is flushed with Gastrografin following surgery.

Feasibility of triple assessment of the anastomosis using an anastomotic checklist

BACKGROUND

Colorectal cancer is the third most common cancer and the second highest cause of cancer mortality in Australia. Despite advances in colorectal surgery, anastomotic leak still occurs in low-risk patients and is a substantial cause of morbidity and mortality. Many operative strategies are used to assess anastomotic integrity such as an air leak test or intraoperative flexible sigmoidoscopy, however an objective anastomotic checklist is yet to be developed and studied. This study aims to develop a photodocumentary anastomotic specific checklist and determine its feasibility for implementation.

METHODS

Patients undergoing left sided colorectal resections with primary anastomosis without a de-functioning ileostomy were prospectively included between May 2021 and December 2022. A photographic checklist assessing anastomotic perfusion, integrity via either air test or endoscopic image, evidence of complete operative doughnut specimens and the assessment of tension was implemented. The feasibility of an anastomotic checklist was externally validated by four independent colorectal surgeons from Australia, New Zealand and United States of America.

RESULTS

The anastomotic checklist was completed in 44 patients. Mean age was 62 years, with 43% male and mean BMI 28. Operations included high anterior resection (45%), low anterior resection (18%), ultra-low anterior resection (20%), reversal of Hartmann's (11%). Median length of stay was 4 days. Complications post operatively were documented in six patients with anastomotic leak in 2% and wound infection in 6.8%. Intraclass correlation coefficients were poor amongst all reviewers with air leak and tension having no inter-reviewer correlation.

CONCLUSION

The introduction of an anastomotic checklist was a feasible tool to systematically assess and document anastomotic integrity. Unfortunately, with the small sample size there was significant discrepancy in inter-observer variability, and this led to poor correlation regarding which patients were typically high risk requiring a temporary ileostomy. Larger studies on the implementation of an anastomotic checklist will be needed to evaluate if it is an inherently feasible approach and if there is an effect on anastomotic leak.

Anastomotic leak in colorectal cancer surgery: Contribution of gut microbiota and prediction approaches

AIM

To monitor prospectively the occurrence of colorectal anastomotic leakage (CAL) in patients with colon cancer undergoing resectional surgery, characterizing the microbiota in both faeces and mucosal biopsies of anastomosis. In a second stage, we investigated the ability to predict CAL using machine learning models based on clinical data and microbiota composition.

METHOD

A total of 111 patients were included, from whom a faecal sample was obtained, as well as biopsy samples from proximal and distal sites in the healthy margins of the tumour piece. The microorganisms present in the samples were investigated using microbial culture and 16S rDNA massive sequencing. Collagenase and protease production was determined, as well as the presence of genes responsible for expressing enzymes with these activities. Machine learning analyses were developed using clinical and microbiological data.

RESULTS

The incidence of CAL was 9.0%, and CAL was associated with collagenase/protease-producing Enterococcus. Significant differences were found in the microbiota composition of proximal and distal biopsy samples, but not in faecal samples, among patients who developed CAL. Clinical predictors of CAL were 5-day C-reactive protein and heart disease, whereas 3-day C-reactive protein and diabetes were negative predictors.

CONCLUSION

Biopsy samples from surgical margins, rather than faecal samples, are the most appropriate samples for exploring the contribution of the intestinal microbiota to CAL. Enterococci are only enriched in the anastomosis after surgery, and their collagenases and proteases are involved in the degradation of the anastomotic scar.

Multicenter Study of Drain Fluid Amylase as a Biomarker for the Detection of Anastomotic Leakage After Ileal Pouch Surgery Without a Diverting Ileostomy

BACKGROUND

Anastomotic leak is the anathema of colorectal surgery. Early diagnosis is an essential segue to early intervention. A temporary defunctioning ileostomy does not prevent an anastomotic leak and presents inherent complications of its own. Drain fluid biomarkers have been studied in colorectal surgery but not in ileal pouch surgery.

OBJECTIVE

This study aimed to assess drain fluid amylase as a biomarker of anastomotic leak after ileal pouch surgery and without a diverting ileostomy.

DESIGN

This was a multicenter prospective observational cohort study.

SETTINGS

The study was conducted at 4 tertiary hospitals in Queensland, Australia.

PATIENTS

This study included elective patients undergoing restorative proctectomy and ileal pouch surgery.

INTERVENTIONS

Measurement of rectal tube amylase and drain fluid amylase.

MAIN OUTCOME MEASURES

The primary measure was observation of increased drain fluid amylase on the day of anastomotic leak.

RESULTS

Fifty-three patients were studied. On the day of anastomotic leak, 4 patients in the anastomotic leak group who experienced an early anastomotic leak recorded a median drain fluid amylase of 21,897 U/L compared with a median drain fluid amylase of 25 U/L for those in the no anastomotic leak group ( p < 0.0001).

LIMITATIONS

This study relies on the anastomotic leak occurring while the pelvic drain is in situ.

CONCLUSIONS

The measurement of drain fluid amylase is a sensitive biomarker of early clinical anastomotic leak in patients undergoing restorative proctectomy with an ileal pouch and when a diverting ileostomy is not incorporated. This simple, inexpensive, and noninvasive test should be considered in all patients with ileal pouches as an adjunct to the clinical diagnosis and differentiation of anastomotic leak from other postoperative complications. See Video Abstract at http://links.lww.com/DCR/B958 .Estudio multicéntrico de la amilasa del líquido de drenaje como biomarcador para la detección de fugas anastomóticas después de una cirugía de reservorio ileal sin ileostomía de derivación.

ANTECEDENTES

La fuga anastomótica es el anatema de la cirugía colorrectal. El diagnóstico precoz es una transición esencial a la intervención temprana. Una ileostomía desfuncionalizante temporal no evita una fuga anastomótica y presenta sus propias complicaciones inherentes. Los biomarcadores del líquido de drenaje se han estudiado en la cirugía colorrectal, pero no en la cirugía del reservorio ileal.

OBJETIVO

El objetivo fue evaluar la amilasa del líquido de drenaje como biomarcador de fuga anastomótica después de cirugía de reservorio ileal y sin ileostomía de derivación.

DISEO

Este fue un estudio de cohorte observacional prospectivo multicéntrico.

AJUSTES

El estudio se realizó en 4 hospitales terciarios en Queensland, Australia.

PACIENTES

Se incluyeron pacientes electivos sometidos a proctectomía restauradora y cirugía de reservorio ileal.

INTERVENCIONES

Medición de la amilasa del tubo rectal y amilasa del líquido de drenaje.

PRINCIPALES MEDIDAS DE RESULTADO

La medida principal fue la observación del aumento de la amilasa en el líquido de drenaje el día de la fuga anastomótica.

RESULTADOS

Cincuenta y tres pacientes fueron estudiados. Los 4 pacientes que experimentaron una fuga anastomótica temprana registraron una mediana de amilasa en el líquido de drenaje de 21 897 U/L el día de la fuga anastomótica en comparación con una mediana de amilasa en el líquido de drenaje de 25 U/L para aquellos en el grupo sin fuga anastomótica (p < 0,0001).

LIMITACIONES

Este estudio se basa en que la anastomosis ocurre mientras el drenaje pélvico está in situ.

CONCLUSIONES

La medición de amilasa en el líquido de drenaje es un biomarcador sensible de fuga anastomótica clínica temprana en pacientes sometidos a proctectomía restauradora con reservorio ileal y cuando no se incorpora ileostomía derivativa. Esta prueba simple, económica y no invasiva se debe considerar en todos los pacientes con reservorio ileal como complemento del diagnóstico clínico y la diferenciación de la fuga anastomótica de otras complicaciones posoperatorias. Consulte Video Resumen en http://links.lww.com/DCR/B958 . (Traducción-Dr Yolanda Colorado ).

An evidence map and synthesis review with meta-analysis on the risk of incisional hernia in colorectal surgery with standard closure

PURPOSE

To assess the incidence of incisional hernia (IH) across various type of incisions in colorectal surgery (CS) creating a map of evidence to define research trends, gaps and areas of future interest.

METHODS

Systematic review of PubMed and Scopus from 2010 onwards. Studies included both open (OS) and laparoscopic (LS). The primary outcome was incidence of IH 12 months after index procedure, secondary outcomes were the study features and their influence on reported proportion of IH. Random effects models were used to calculate pooled proportions. Meta-regression models were performed to explore heterogeneity.

RESULTS

Ninetyone studies were included reporting 6473 IH. The pooled proportions of IH for OS were 0.35 (95% CI 0.27-0.44) I² 0% in midline laparotomies and 0.02 (95% CI 0.00-0.07), I² 52% for off-midline. In case of LS the pooled proportion of IH for midline extraction sites were 0.10 (95% CI 0.07-0.16), I² 58% and 0.04 (95% CI 0.03-0.06), I² 86% in case of off-midline. In Port-site IH was 0.02 (95% CI 0.01-0.04), I² 82%, and for single incision surgery (SILS) of 0.06-95% CI 0.02-0.15, I² 81%. In case of stoma reversal sites was 0.20 (95% CI 0.16-0.24).

CONCLUSION

Midline laparotomies and stoma reversal sites are at high risk for IH and should be considered in research of preventive strategies of closure. After laparoscopic approach IH happens mainly by extraction sites incisions specially midline and also represent an important area of analysis.

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.