Laparoscopic vs Ultrasound Guided TAP Block in Colorectal Surgery. A Randomised Controlled Study.

A randomized clinical trial aiming to compare two different techniques of performing a nerve blockage of the abdominal wall. When performing surgery on the colon and rectum surgeons often use a minimal invasive technique called Laparoscopic surgery. In this technique small incisions in the abdominal wall are used to put special ports trough into the abdomen so that surgical instrument can be inserted. To minimize the pain caused by these port-holes, a so-called Transversus Abdominus Plane (TAP) nerve block is performed directly after the surgery before the patient wakes up from narcosis.

This procedure is normally performed by the anesthesiologist using ultrasound to guide a needle to the right depth or "plane" in the abdominal wall where the nerves are gathered. When in the right position a local anesthetic is injected that will block the nerves and thereby anaesthetizing the abdominal wall for the first post-operative day.

Recently an alternative way of guiding the needle to the right position has been presented. By using a laparoscopic camera the surgeon can easily guide the needle and inject the local anesthetics during surgery. This way of performing the TAP block may save valuable time compared to the more cumbersome ultrasound guided technique while also not needing an extra anesthesiologist in the operating theater.

In this study we aim to include participants selected for elective minimal invasive surgery of the colon or rectum, where a TAP block is normally performed. The participant will be randomized to either a TAP block performed by the surgeon using laparoscopic guidance or by an anesthesiologist using ultrasound guidance. The intended surgery in itself will not be altered.

During surgery we will measure TAP procedure time, total surgical time, total duration of anesthesia and total time spent in the operating theater. The following 2 postoperative days we will measure experienced pain using a validated pain-score (VAS) and measure the total consumption of pain medication. 2 days after surgery the study ends for the participant and there is no further follow up.

By conducting this study we can determine whether a laparoscopic guided TAP by the surgeon, compared to a traditional ultrasound guided by the anesthesiologist; gives a shorter procedure time, shorter time of narcosis and reduced consumption of pain medications post-operative while still not affecting the experienced pain by the participant.

At Danderyds hospital in Stockholm, since 2010, we are conducting patient care according to international evidence based Enhanced Recovery After Surgery (ERAS) protocols. Within colorectal surgery Danderyds hospital has been appointed ERAS Centre of Excellence due to documented favorable clinical results and a particularly suitable infrastructure for clinical research. The protocol comprises of 24 evidence-based interventions aimed at reducing so called surgical stress and promote early recovery after surgery. All interventions are executed in the same way for all patients. Optimal post-operative pain relief constitutes one of the 24 interventions and within this section a few methods are recommended. Transversus abdominus plane (TAP) block is one of those, and have been shown to reduce post-operative pain, reduce opioid consumption and elevate mobilization after surgery.

A TAP block is performed by injecting local anesthetics into the nervous plane in between the transverse and external muscles in the abdominal wall, and thereby blocking the nerves responsible for transmitting pain from the laparoscopic holes created during surgery.

Normally this TAP blockage is performed by the anesthesiologist using ultrasound to guide the needle for injection into the right plane of the abdominal wall. A procedure that can be cumbersome and that in our hospital setting takes around 30 minutes and is executed directly after the surgery but before the patient is alleviated of narcosis.

A novel technique has recently been described to guide the needle into the right position for the TAP block. In this technique the surgeon will use the laparoscopic camera and the port holes already made during surgery to visualize the inside of the abdominal wall, and by landmarks and a specially described bulging of the peritoneum as a marker, guide the needle from the outside and inject local anesthetics into the right plane. This method described by earlier studies has a procedure time at around 5+-1 minutes and has the benefit of not needing ultrasound or any other equipment not already present for the surgical procedure.

In this study we aim to include participants selected for elective robotic-assisted or laparoscopic minimal invasive surgery of the colon or rectum, where a TAP block is normally performed. The participant will be randomized to either a TAP block performed by the surgeon using laparoscopic guidance or by an anesthesiologist using ultrasound guidance. The intended surgery in itself will not be altered.

During surgery we will measure TAP procedure time, total surgical time, total duration of anesthesia and total time spent in the operating theater.

The following 2 postoperative days we will measure experienced pain using Visual Analog Scale (VAS) and measure the total opioid consumption. 2 days after surgery the study ends for the participant and there is no further follow up.

Previous studies on this technique have shown comparable or even better pain relieving efficacy compared to the ultrasound guided technique.

By conducting this study we can determine whether a laparoscopic guided TAP by the surgeon, compared to a traditional ultrasound guided TAP by the anesthesiologist; gives a shorter procedure time, shorter time of narcosis and reduced consumption of pain medications post-operative while still not affecting the experienced pain by the participant

Eligibility Criteria:
Inclusion Criteria:

* Elective laparoscopic or robot-assisted colorectal surgery.

Exclusion Criteria:

* IBD
* documented alcohol addiction
* documented opioid addiction
* unable to be assessed by Visual Analog Scale (cognitive impairment or other)
* Allergy against the local anaesthetic used, Ropivacain.