Is a transversus abdominis plane (TAP) block more effective than local anaesthetics or no block to treat post-surgical pain in women undergoing minimally invasive gynaecologic surgery?
Key messages
Women undergoing minimally invasive (key-hole) gynaecologic surgery who receive a TAP block to reduce the amount of pain felt after surgery are unlikely to experience large differences in pain or strong pain medicine needed when compared to those who do not receive the TAP block.
What is a TAP block?
A TAP block numbs the nerves in the abdomen by injecting a numbing medicine through the skin and into the space between the surface and deeper abdominal muscles.
Why is this important for women undergoing minimally invasive gynaecologic surgery?
Controlling pain following surgery is important for successful recovery. Well-controlled pain leads to a shorter hospital stay, less time away from work, and less chance of long-lasting pain. Many women undergoing surgery receive shots of numbing medicine right next to their incisions. However, this type of numbing medicine wears off quickly. Giving the same numbing medication deeper, within the muscles of the abdominal wall, allows it to spread out more and may slow down how quickly the effect wears off.
What did we want to find out?
We wanted to know if women who had a TAP block had less pain and used less pain medicine one day after surgery, than women who received no injection, an injection of numbing medicine at the incision sites, or a pretend block. We wanted to know whether women who had a TAP block experienced serious harmful side effects as a result of the block. Finally, we wanted to know if women who had a TAP block experienced more side effects of strong pain medicine, such as nausea, vomiting, or sleepiness following surgery.
What did we do?
We searched for studies that compared women who had a TAP block to those who had no block, an injection of numbing medicine at their incision site, or a pretend block for their key-hole gynaecologic surgery. Studies had to choose women at random (women had an equal chance to be assigned to all groups).
What did we find?
We found 21 studies with 1645 adult women who were having key-hole gynaecologic surgery. The studies were conducted in 10 different countries, between 2011 and 2023.
We analysed the results in three comparisons: TAP block compared to no block, TAP block compared to an injection of numbing medicine at the incision site, or TAP block compared to pretend block.
Women undergoing key-hole gynaecologic surgery who receive a TAP block may experience slightly less pain on the day following surgery than those who receive a local numbing injection or a pretend block.
Women who receive a TAP block may have little or no difference in their strong pain medicine needs than those who receive no block, numbing medicine at incision sites, or a pretend block.
None of the studies reported any serious harmful effects related to the TAP block.
Women who receive a TAP block may experience little to no difference in nausea or vomiting compared to those who receive no block, numbing medication at incisions sites, or a pretend block.
We are uncertain whether these results are clinically meaningful.
What are the limitations of the evidence?
We are moderately confident that women who have a TAP block experience less pain than those who receive a pretend block. We are less confident whether they experience less pain than those who have no block or a local numbing injection. It is possible that some of the women might have known which pain control procedure they had, which could have influenced the results.
We are uncertain about the results of the need for strong pain medicine, because it is possible that some of the women might have known which pain control procedure they had, and because there were too few studies that measured this outcome.
We are moderately confident that the TAP block is not associated with serious harmful side effects. We have moderate to low confidence that there is little to no difference in nausea and vomiting amongst all the women, in all the groups. There were too few studies reporting this outcome to be certain of the results.
How up to date is this evidence?
This review is up-to-date to 6 December 2024.
Amongst women undergoing minimally invasive gynaecologic surgery, we did not find a clinically meaningful effect of TAP block on postoperative pain or opioid consumption. However, there may be a small reduction of pain using TAP blocks compared to local anaesthetic or sham blocks. The TAP block is probably safe, since no adverse events were noted amongst the 525 women who received a block, and for whom safety data were available. The evidence is limited by heterogeneity in the results, risk of bias in the studies, and assumptions made for synthesis when combining data.
To evaluate the benefits and harms of single-shot transversus abdominis plane blocks for the prevention of postoperative pain in women undergoing laparoscopic and robotic gynaecological surgery compared to no block, sham block, or injection of local anaesthetic.
We searched CENTRAL, MEDLINE, Embase, two trials registers, and handsearched abstracts to 6 December 2024.
The review had no dedicated funding.
Protocol (2022): DOI: 10.1002/14651858.CD015145.