PINPOINT endoscopic fluorescence perfusion assessment of colorectal anastomoses – Will this impact outcomes? The PILLAR II Study.

Michael J Stamos, MD, on behalf of the PILLAR II Study Investigators

University of California, Irvine

Objective of the Study/Technique
Anastomotic leakage following colorectal resection and primary anastomosis is an important clinical problem that causes increased morbidity and mortality to the patient, especially in low anterior resections (LAR). The incidence of anastomotic leaks reported in the literature varies between 0.5% and 30%. Inadequate perfusion at the anastomotic site is believed to be a major determinant of leak. The PINPOINT® Endoscopic Fluorescence Imaging system (Novadaq Technologies Inc., Ontario, Canada) allows the surgeon to intra-operatively assess tissue perfusion during laparoscopic left-sided colectomy. The utility of intraoperative assessment of tissue perfusion using the PINPOINT® system is being evaluated in a multicenter clinical trial (PILLAR II-www.clinicaltrial.org)

Description of the methods
PINPOINT consists of a rigid endoscope, a camera and a light source optimized for both high definition (HD) white light and Near Infra Red Fluorescence (NIRF) images. The NIRF images are acquired following administration of an intravenous bolus of indocyanine green (ICG), an agent which is confined to the vascular space and fluoresces in the NIR when excited with light at the appropriate wavelength. A separate injection of ICG is given for each image sequence acquisition and multiple sequences can be acquired over the course of a surgery. Perfusion is assessed by qualitative inspection of the NIRF images. Images can be displayed separately or in a combined “PINPOINT” mode with the NIRF image superimposed on the HD white light image, thus providing anatomical context for the NIRF image.

Perfusion at the planned distal resection margin of the colon is assessed following division of the relevant blood vessels and mesentery. A bolus of ICG is injected and the area of interest viewed in PINPOINT mode during the passage of the bolus through the field of view. The colon may then be transected within an area of good perfusion as assessed by the PINPOINT image. Following completion of the anastomosis, perfusion of the mucosal aspect is assessed. The PINPOINT endoscope is inserted trans-anally using a customized introducer, advanced to the anastomotic line, a bolus of ICG injected and the tissue is viewed in PINPOINT mode.

Results
Preliminary experience in 9 patients indicates that assessment of perfusion at both the colonic transection margin and the mucosal aspect of the completed anastomosis during laparoscopic LAR are feasible. Further evaluation will indicate the frequency of alteration in operative plans as indicated by the perfusion assessment.

Conclusions
It is anticipated that assessment of perfusion at the colonic resection margin using the PINPOINT system may decrease the incidence of postoperative anastomotic leak. Subsequent perfusion assessment of the completed anastomosis, with the colon in its final anatomical position and tension, may assist in decision making regarding the need for a diverting ileostomy.

Session: Poster Presentation

Program Number: P617