There is a significant learning curve associated with laparoscopic inguinal hernia repair, particularly with the totally extraperitoneal (TEP) approach. To assist surgeons undertaking this operation, I have outlined what I see as important technical aspects of the operation, based on my experience of over 8000 TEP repairs.
Skin incision within the umbilical scar, with bias towards side to be operated on (in case there is debate in the future re which side has been repaired already).
Incision in medial anterior rectus sheath on side of hernia (Andrew favours vertical, but transverse = ok)
Purse string across edges of slit in sheath acts to create seal around 10mm Hasson cannula.
Retract rectus muscle laterally.
Initial space dissection either with balloon or end of the 10mm scope.
5mm ports in midline, through linea alba. Support anterior abdominal wall with Hasson while introducing port, to control penetration.
Tip: both dominant hand and non-dominant hand instruments should always have their tips close together when dissecting inguinal hernias. Much of the dissection involves traction and counter-traction, which is much easier to achieve if the non-dominant hand instrument supports the tissue to be dissected close to the action.
Important: Dissect well laterally and anteriorly before attending to hernia sac. If sufficient space has been developed, not only will the remainder of the operation be easier to achieve, but mesh placement will be more straightforward and inadvertent pneumoperitoneum less likely to cause constriction of the operating space.
The defect is not readily apparent; it only becomes so as the extraperitoneal fatty tissue is separated from the attenuated transversalis fascia, which is tented into the extraperitoneal space by the CO2 pressure. It then balloons out through the posterior wall of the inguinal canal, revealing the extent of the hernia defect. Do not mistake this fascia for the peritoneum; the peritoneum is usually not seen when reducing direct hernias.
To avoid a haemoserous collection accumulating in the hernia defect post-repair, grasp the transversalis fascia of the defect and draw it in so that it can be tacked to the adjacent superior pubic ramus, or taken up with an endoloop, thereby obliterating the deadspace of the defect, which will otherwise trap fluid, forming a palpable lump at the site of the just-repaired hernia. NB do not pick up the cord tissues when looping the attenuated transversalis fascia.
Larger sacs are easier to deal with if dissection around the circumference of the sac is achieved early on in the process of sac dissection out of the inguinal canal, off the underlying cord structures. This needs to be done anyway, if the plan is to transect the sac, though it is my preference to completely dissect the sac without transection; the fundal remnant of a transected sac has the potential to form a hydrocoele of the cord.
Chose a mesh which has the handling characteristics that suit best. Wide pore is better, as scar tissue grows through the pores; with small pore size, there is more of a tendency for scar tissue to encapsulate the entire mesh, resulting in greater contraction. Understand that all meshes contract to some extent. Lightweight meshes tend to be too floppy and are more difficult to position satisfactorily against the inguinal wall. Lightweight may result in less possibility of mesh awareness postop, but this is not a factor when the mesh is deep to the muscle layers, as for laparoscopic inguinal hernia repair.
I favour a flat 150mm x100mm mesh. Shaped meshes may be easier to position when learning the operation. Beware of meshes with splits or folds; any mesh that is designed to encircle structures (the spermatic cord) creates potential for those structures to be constricted as the inevitable mesh contraction takes place.
If the mesh is introduced as a cylinder, try to position it in the medial-lateral axis before unfurling it. The centre of the mesh should be along the line of the ilio-pubic tract.
If penetrative fixation is used, fix along the medial edge only, onto the surface of the superior pubic ramus +/- the linea alba in the midline. This avoids injury to soft tissues (muscles, ligaments). General surgeons tend to feel more comfortable fixing into soft tissues alongside the pubic ramus, rather than into the bone surface, but there is a risk that the patient might not feel so comfortable after the operation. Lack of lateral penetrative fixation allows the mesh to contract from lateral to medial across the inguinal region, bearing in mind that all meshes contract to some extent (up to 30%, depending on type). Properly positioned mesh will be trapped against the abdominal wall by the peritoneum, with the weight of the abdominal contents behind it. Remember, there is very little movement within this area, as it is within the bony frame of the pelvis.
Recurrences tend to occur under the posterior border of the mesh, particularly the postero-lateral corner. I have never seen a recurrence over the anterior border. Make sure the posterior edge is tucked under the peritoneum (and sac), which has been dissected away from the inguinal area.
If self-adhering mesh (ProGrip) or glue is used, position the mesh so that it extends a 10mm or so across to the contralateral side in the midline, as it will contract with time, potentially exposing the medial aspect of the posterior wall of the inguinal canal. There is sufficient lateral cover with a 150mm wide piece of mesh to allow for this.
These are difficult to reduce laparoscopically. Use of a diathermy hook to disrupt the lacunar ligament medially will facilitate the process.
These defects are readily accessible in the extraperitoneal plane; the dissection is essentially the same as for an inguinal hernia, it just needs to be extended in a cephalad direction anteriorly.
These rare hernias are also very amenable to an extraperitoneal approach, but the patient needs to be positioned lying on the side (with the hernia uppermost) and the ports positioned in the lateral iliac fossa.
Recurrent hernias, post laparoscopic repair
These need to be done with a TAPP approach. The recurrence is always around the original mesh, so it is a matter of mobilising the adjacent peritoneum, then dissecting the sac out of the defect, before adding an extra piece of mesh to provide adequate cover to prevent further recurrence. The new mesh should overlap the original. It can be fixed to the original mesh and elsewhere as needed (with care), before covering the new mesh with the mobilised peritoneum and the peritoneum of the hernia sac.
Repair post radical prostatectomy
With experience, these are usually able to be repaired using the TEP approach. Balloon dissection at the start of the operation should be avoided, as the peritoneum may tear where it is adherent to the abdominal wall through scarring. The trick is to dissect well laterally at first, before swinging the dissection in a medial direction. Hernias post radical prostatectomy are almost invariably indirect, as scarring involving the posterior wall of the inguinal canal prevents direct herniation. The indirect sac is, by necessity, free of scar tissue and can be dissected out of the inguinal canal in the usual manner. Difficulty dissecting space for the mesh medially is very variable and the amount of scarring encountered does not seem to have any relationship to the approach used for the radical prostatectomy (open vs. laparoscopic vs. robotic). A combination of judicious sharp and blunt dissection is required, making sure to keep against the posterior wall of the inguinal canal. The shape of the mesh may need to be modified somewhat if it is not possible to completely expose the posterior wall.
No physical restrict is necessary; the mechanics of laparoscopic inguinal hernia repair means that the area is stronger than it ever has been as soon as the mesh has been positioned correctly!