The Transversus Abdominis Plane Block (TAP) has become one of the most established and
frequently performed trunk wall blocks for perioperative analgesia in abdominal surgical
procedures. A TAP block is a so-called trunk wall block where a targeted injection of
high volumes of local anesthetics is made into a space between two muscle fascias, the
so-called inter-fascial space. In this inter-fascial space, the cutaneous nerve branches
of various anterior rami of the spinal nerves run and innervate somatosensory in the
respective dermatome, skin, soft tissues, and bones, as well as the outer layers of the
pleura and peritoneum. Specifically, in a TAP block, the nerve fibers of the spinal
nerves from the spinal segments Th6 to L1 can be anaesthetized by applying local
anaesthetics between the Musculus obliquus internus abdominis and the Musculus
transversus abdominis. The block produces somatic analgesia of the skin, muscles, and
bony structures. Visceral analgesia of the internal organs is not achieved. Therefore,
the TAP block mainly has an indication within the framework of a multimodal pain concept
to save central and peripheral analgesics.
In the literature, it is shown that especially laparoscopic procedures benefit from a TAP
block in terms of reducing postoperative reported pain intensity and reducing
postoperative opioid requirements. Compared to simple wound infiltration with a local
anaesthetic or simple local anaesthesia of the trocar insertion sites in a laparoscopy,
the TAP block has been shown to be a more effective method in multiple studies.
The so-called Transversus Abdominis Plane compartment can be reached using various
approaches (posterior, lateral, subcostal) and puncture techniques (landmark-based,
ultrasound-guided, and surgical). A lateral approach is used primarily for analgesia in
lower abdominal surgery (e.g., inguinal hernia repair). A subcostal approach is used
primarily for analgesia in upper abdominal/supraumbilical surgery (e.g.,
cholecystectomy). A dual TAP block or '4 quadrant block,' the combination of a lateral
with subcostal TAP block, could achieve better abdominal distribution of the local
anaesthetic and more complete analgesia for the lower (T10-T12) and upper (T6-T9)
abdomen.
The goal of this monocentric, prospective, randomised study is to compare an
anesthesiological, ultrasound-guided "Transversus Abdominis Plane (TAP) Block" with a
laparoscopic, landmark-based "Transversus Abdominis Plane (TAP) Block" in two parallel
study arms.
Anaesthesia Induction and maintenance in both groups are standardised and similar.
The main questions to answer are:
Primary Hypothesis: There are no differences in postoperative pain perception and
analgesic requirements between the anaesthesiological ultrasound-guided and the surgical
laparoscopic landmark-based TAP block
Secondary Hypothesis: There are no significant differences in the duration of the
procedure between the anaesthesiological, ultrasound-guided and the surgical laparoscopic
landmark-based TAP block.
A sample size calculation was performed before study start. The hypotheses will be
verified by suitable statistical analysis. The randomization process is performed
preoperatively using a closed envelope ('Sealed Envelope') that assigns a patient to one
of the two intervention groups.