Introduction
To date sedation protocol for colorectal endoscopic submucosal dissection (ESD) has not been standardized. (1)
In a recent Italian survey 48,2% of responders perform colorectal ESD with anaesthesiologist assisted deep sedation. (2)
A randomized controlled trial showed an higher incidence (37.9%) of procedure discontinuation in upper GI ESD when performed with midazolam administration.(3)
The aim of this study was to analyse the efficacy and safety of colorectal ESD performed under endoscopist assisted conscious sedation with midazolam continuous infusion (MCI).
Aims & Methods
Consecutive patients who underwent standard and hybrid ESD for colorectal lesions in our institution from April 2017 to September 2023 were prospectively analysed.
In all procedures, a bolus of 0.05mg/kg followed by 0.07mg/kg/h continuous infusion of midazolam was administered with any further boluses and additional drugs (meperidine and scopolamine butyl bromide) according to the patient's level of sedation and pain control.
The main outcome was the incidence of discontinuation of the procedure due to a poor response to sedation.
The second outcome was the incidence and type of sedation side effects.
Treatment outcomes, including adverse events were evaluated for each lesion.
Additional drugs administration and past medical history were collected.
Results
101 ESDs were performed in the period of analysis.
In 5 out of 101 procedures (4.9%) was registered a discontinuation due to poor response to MCI sedation and was requested a conversion to anaesthesiologist assisted deep sedation to complete the procedure.
N. 96 cases were considered for safety analysis (M/F 49/47, median age 70yrs [IQR 14.25]; mean BMI 25.2 [SD: 2.92]).
Sedation drug doses are listed in Table 1.
Lesions had a mean size of 37.1mm [range 10-80], being mostly located in the rectum (96.9%).
En bloc rate was 85,4% , while R0 rate was 92,7%.
The incidence of sedation side effects was 13,5% (13/96): in 12 patients occurred bradycardia, while in 1 patient hypotension.
All those side effects were conservatively managed with medical therapy without occurrence of cerebrovascular or cardiac ischemic events.
In the univariate analysis, sedation side effect occurrence was associated with additional intraprocedural scopolamine butyl bromide administration and patient history of respiratory disease (p<0.05).
Among early adverse events, in 3 patients occurred superficial muscular damage, which was managed endoscopically, while in one patient occurred perforation, which required surgery.
Regarding late adverse events, in 5 patients was reported a late bleeding, which was treated endoscopically with success, whereas in 6 patients occurred post-polypectomy syndrome and in 4 patients occurred urinary retention, both resolved with medical therapy
Table 1. Sedation drug doses
| Induction + Continuos infusion | Mg (mean) |
| Midazolam | 19 |
| Additional bolus | N(%) | Mg (mean) |
| Midazolam | 91 (95) | 2.5 |
| Scopolamine | 37 (38,5) | 6.04 |
| Meperidine | 80 (83,3) | 66.56 |
Conclusion
The use of MCI is a safe and effective sedation option for colorectal ESD procedures, with a low rate of procedure discontinuation.
References
(1) Kinugasa H, Higashi R, Miyahara K, et al. Dexmedetomidine for conscious sedation with colorectal endoscopic submucosal dissection: a prospective double-blind randomized controlled study. Clin Transl Gastroenterol. 2018;9(7):167
(2) Maselli R, Iacopini F, Azzolini F, et al. Endoscopic submucosal dissection: Italian national survey on current practices, training and outcomes. Dig Liver Dis. 2020;52(1):64-71
(3) Ominami M, Nagami Y, Shiba M, et al. Comparison of propofol with midazolam in endoscopic submucosal dissection for esophageal squamous cell carcinoma: a randomized controlled trial. J Gastroenterol. 2018;53(3):397-406
Disclosure
V. Cennamo: Member of the scientific board of Olympus Italia; Consultant for Novità Medicali and Euromedical. All other authors disclosed no financial relationships.
