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Fortelny. Mini-invasive Surg 2021;5:16 https://dx.doi.org/10.20517/2574-1225.2021.21 Page 7 of 11

hernias. Nevertheless, the subgroup analysis shows that glue-fixation in medial hernias was significantly
more frequently used compared to non-fixation. Since no evaluation is available regarding the size and type
of fixation of medial inguinal hernias, the interpretation in this regard should also be viewed with caution.

For the TAPP procedure, only 2 RCTs [51,52] comparing non-fixation with staple fixation have been published
to date. In 1999, Smith et al. reported a recurrence rate after median follow-up of 16 months (range, 1-32
[51]
months) of 0% after non-fixation and 1% after staple fixation without significant difference (P = 0.09).
Furthermore, no significant difference was detected in operative time and chronic pain between the two
groups. Limitations of this study have to be considered regarding the short time of follow up and the
number of patients followed up of only 65% by examination and 22.2% by telephone. In the study by Li
[52]
et al. , male patients with primary, unilateral inguinal hernia, defect size < 4 cm diameter were randomly
allocated to non-fixation or staple fixation. After a median follow up of 11.5 months after non-fixation and
11.2 months after staple fixation, no recurrences were found. Postoperative VAS pain scores up to 6 months
for the non-fixation group were significantly lower than in the fixation group. The quality of life regarding
physical function, physical role, bodily pain, and general health in the non-fixation group was significantly
better than in the fixation group. This RCT also had limitations regarding the very short follow-up period
and the inclusion criterion restricted to smaller than 4-cm defect size.

In summary, the question of non-fixation in TEP and TAPP has limited answerability. The lowest common
denominator for low-risk non-fixation of meshes in TEP and TAPP techniques seems to be primary
unilateral male inguinal hernias with exclusion of medial hernia types with a defect diameter of ≥ 3 cm.

Discussion
The appropriate technique in TEP and TAPP repair is the most important requirement of prevention of
postoperative pain. The dissection in the right plane with preserving the protective layers such as spermatic
sheath to prevent nerve injury and to avoid any coarse grasp of the spermatic cord are basic rules to be
observed. The preparation of the landing zone has to be sufficient for a mesh implantation of at least 10 cm
by 15 cm. In the special case of direct hernia with a defect size of 3 cm and more the mesh size has to be
larger, e.g., 12 cm by 17 cm to guarantee a sufficient overlap of at least 3 cm over the midline. In addition,
the inversion of the dilated transverse fascia seems to prevent postoperative seroma occurrence in these
cases. Following these crucial steps of TEP or TAPP are mandatory to achieve best outcomes regarding
postoperative pain and recurrence rate.

The choice of the optimal mesh for laparo-endoscopic inguinal hernia repair has been discussed for years
with the question of light or heavy weight. Until recently, lightweight meshes were clearly preferred in terms
of pain and reduced foreign body reaction, but an RCT with long-term results has changed the evidence .
[53]
In this 5-year follow-up RCT study in TEP repair of primary unilateral inguinal hernias, the recurrence rate
was significantly increased after the use of lightweight mesh (UltraPro) compared to the use of heavyweight
®
mesh. This publication did not remain uncommented . Since the classification of medial hernias in this
[54]
study is based on the Nyhus classification and not on the EHS classification with differentiation of
[56]
[55]
defect sizes (MI, MII and MII), the MIII hernia cannot be evaluated selectively.
The studies, already mentioned in the seroma chapter regarding the closure or shortening of the dilated
transverse fascia have not only led to a reduction in seroma formation but also to a decrease of the
recurrence rate. This relationship seems quite plausible. Considering the bending stiffness of small pore-
sized/heavyweight meshes compared to large pore-sized/lightweight meshes, significant differences can be
found, which are especially important when there is no tissue directly under the mesh but an empty space.