Methylene blue fluorescence of the ureter during colorectal surgery

Abstract

BackgroundIatrogenic ureteric injury is a serious complication of colorectal surgery. Incidence is estimated to be between 0.3 and 1.5%. Of all ureteric injuries, 9% occur during colorectal procedures. Ureteric stents are utilised as a method to reduce the risk of injury; however, these are not without risk and do not guarantee prevention of injury. Fluorescence is a safe and effective alternative for intraoperative ureteric localisation. This proof of principle study aims to assess the use of methylene blue to fluoresce the ureter during colorectal surgery.MethodPatients undergoing elective colorectal surgery were included in this open label, non-randomised study. Methylene blue was administered intravenously at varying doses (0.25–1 mg/kg) over 5 min, 10–15 min prior to entering ‘ureteric territory.’ Fluorescence was assessed using the PINPOINT Deep Red laparoscopic system at fixed time points by the surgeon and an independent observer.Results42 patients received methylene blue; 2 patients were excluded from analysis. Of the 69 ureters assessed, 64 were seen under fluorescence. Of these, 14 were not visible under white light. 50 ureters were observed with both fluorescence and white light with 14 of these being seen earlier with fluorescence. In ten cases, fluorescence revealed the ureter to be in a different location than suspected.ConclusionFluorescence is a promising method to allow visualisation of the ureter, where it is not identified easily under standard operative conditions, thereby improving safety and reducing operative time and difficulty.Electronic supplementary materialThe online version of this article (10.1007/s00464-018-6219-8) contains supplementary material, which is available to authorized users.

Currently available and experimental dyes for intraoperative near-infrared fluorescence imaging of the ureters: a systematic review

“…Four good quality human studies and one animal study were identified (Table 2 , Supp. Table 3 and 4) [ 17 – 21 ]. Matsui et al reported visualization of the ureters in pigs after intravenous (IV) injection of methylene blue (MB), prompting clinical translation by others [ 18 – 21 ].…”

“…Table 3 and 4) [ 17 – 21 ]. Matsui et al reported visualization of the ureters in pigs after intravenous (IV) injection of methylene blue (MB), prompting clinical translation by others [ 18 – 21 ]. In humans, feasibility and dose-finding studies described MB use in open and laparoscopic abdominal procedures [ 18 – 21 ].…”

“…Matsui et al reported visualization of the ureters in pigs after intravenous (IV) injection of methylene blue (MB), prompting clinical translation by others [ 18 – 21 ]. In humans, feasibility and dose-finding studies described MB use in open and laparoscopic abdominal procedures [ 18 – 21 ]. MB was injected IV with a dose between 0.25 and 1.0 mg/kg and allowed ureteral visualization after 10–15 min [ 21 ].…”

“…1 Visualization of the ureter using methylene blue during open surgery. Reproduced with permission from Barnes et al 2018 [ 21 ] (CC BY 4.0) …”

Iatrogenic ureteral injuries and their prevention in colorectal surgery: results from a nationwide survey

“…Early results suggest a promising future for both techniques. Using the fluorescence of methylene blue excreted in urine after intravenous injection, Barnes et al [32] were able to identify 14 out of 64 ureters that were not visible in standard white light, and in 10 cases the technique showed the ureter to be in an unexpected location. However, these techniques are costly and technically difficult to develop for research teams and industrial partners.…”