Indocyanin Green Fluorescence Evaluation of Colonic Perfusion During Elective Open Abdominal Aortic Aneurysm Repair

Colonic ischaemia is a rare but devastating complication of open aortic aneurysm repair and is associated with high morbidity and a mortality of up to 50%. The aim of this study was to determine the safety and effectiveness of using indocyanin green florescence (ICG) to interrogate colonic perfusion intra-operatively.

Prospective observational study.

All elective open abdominal aneurysm repairs over a 6 month period underwent colonic perfusion interrogation with ICG according to a pre-defined protocol. Patient demographics and imaging findings were recorded prior to surgery. ICG was given just prior to laparotomy closure. Time to florescence was measured from the start of IV administration to surgeon defined maximal florescence of the sigmoid colon.

Ten patients fulfilled the inclusion criteria. All patients were male with an average age of 69.7 years. Inferior mesenteric artery reimplantation was performed in 5 patients. Median colonic fluorescence time was 58 s. No complications related to ICG were identified. A single patient had clinical concern of colonic ischaemia and delayed perfusion (>3 min) on ICG; colorectal opinion advised not for immediate resection. At relook laparotomy, ischaemic colon at the area of demarcation was noted and a Hartmann's procedure was performed. No other patients had delayed perfusion and no further episodes of colonic ischaemia were noted. IMA reimplantation did not show statistical difference in colonic ICG time (P = .81, 95% CI -1.98 to 2.45). There was no statistical difference between operating times between the cohort and all repairs performed 6 months before the data collection (P = .59, 95% CI -.73 to 1.24).

In this pilot study ICG appears to be a safe and useful adjunct in objective assessment of colonic perfusion during open AAA repair. Further research is required to fully determine its role in this cohort of patients.