Minimally Invasive Surgery of the Groin: Inguinal Hernia Repair

The minimally invasive surgical technique for inguinal hernia repair (eTEP and TAPP) are gaining acceptance among surgeons worldwide. With the superior benefits of the laparoendoscopic techniques (less postoperative pain, numbness, and chronic pain, fewer complications, and faster return to normal activities), the protocolization and standardization of these approaches are essential to improve patient outcomes and reduce costs. Improved laparoscopic skills, well-selected patients, simulator training, and anatomy knowledge of the groin are the cornerstone for these approaches. We recommend starting the learning curve with the TAPP procedure, because it is easier to get familiarized with the anatomical landmarks of the pelvis and groin.


Introduction
When dealing with groin hernia, we believe that surgeons must be familiarized with an open technique (Lichtenstein), a posterior open technique (e.g., Rives-Stoppa), a non-mesh technique (Shouldice or McVay), and a laparoendoscopic technique (TAPP or eTEP). The former is because the groin hernia has a lifetime occurrence of 27-43% in men and 3-6% in women [1]. Therefore, inguinal hernia repair (IHR) is one of the most common surgeries performed worldwide, doing approximately 20 million each year [2].
It is now well recognized that laparoendoscopic techniques are superior to open approaches concerning less postoperative pain, numbness [3], chronic pain, fewer complications, and faster return to normal activities [2-4. Nevertheless, longer operative time, increased costs, and major complications such as great vessels and intestinal injuries are attributable to the laparoendoscopic approach [2][3][4]. Even though laparoendoscopic surgery is more expensive than open procedures [2], improved surgical skills, experienced surgeons, high-volume centers, and some patient characteristics (e.g., Bilateral inguinal hernia) enhance this approach [2,[4][5][6].
Improved laparoscopic skills, well-selected patients, simulator training, and anatomy knowledge of the groin are the cornerstone for these approaches.

Anatomical considerations
The myopectineal orifice (MPO) is an inherently weak area of the abdominal wall where the direct, indirect, femoral, and oblique hernias occur [7], being delimited medially by rectus abdominis muscle, inferiorly by pectineus ligament, laterally by psoas muscle, and superiorly by the transverse arch (transversus abdominis and internal oblique muscle) [8]. The anatomical landmarks are described in Figure 1.
Two classic triangles have been described in the laparoscopic inguinal view: The triangle of doom (Figure 2) where the external iliac artery and vein are, and the triangle of pain (Figure 2), within this triangle, are from lateral to medial: the lateral femoral cutaneous nerve, the femoral branch of the genitofemoral nerve and the femoral nerve.  A more didactic description of the MPO's posterior visualization dividing this region into three zones and five triangles was described to facilitate the comprehension and recognition of anatomical structures during MISr [8] (see Figures 3 and 4).

Surgical aspects
Even though the eTEP and the TAPP require a different initial approach, both techniques need to accomplish the MPO's critical view to assurance a correct mesh placement after the creation of the peritoneal pocket.

Indications and contraindications
The indications to perform a MISr of inguinal hernia are the same as those for an open approach. The more important indications to do MISr are: knowledge of the  technique with a clear laparoscopic anatomy concept, having laparoscopic skills for intracorporeal suture, and bimanual dissection capacity. In the case of an incarcerated or strangulated hernia, we recommend the TAPP approach to inspect the bowel; if small bowel resection must be done, intracorporeal stapler use or exteriorization of the bowel through the umbilical port (minilaparotomy of 5 cm) can be used.
The contraindications are the patient's intolerance to pneumoperitoneum, childhood, and pregnancy after the second trimester. Relative contraindications are severe ascites, strangulated hernia, recurrence inguinal hernia after a posterior approach.
As for the initial cases, we recommend starting with small, unilateral hernias and progressively, increase the difficulty of the cases.

Preoperative planning
Patient: patient's position on the operating table is supine with both arms secured at their respective side. Bladder drainage with a Foley catheter is unnecessary if the patient urinates immediately before entering the operating room; We suggest draining the bladder with a Foley catheter during the initial cases.
The surgeon's position is on the hernia's contralateral side (Dr. Ploneda-Valencia usually operates at the patient's head). The camera's operator is on the hernia's side (or at the opposite of the hernia if the surgeon is at the patient's head). The operating table is kept in the Trendelenburg position with a contralateral rotation of the hernia. The monitor is placed at the patient's feet.
Comment: Our anesthetist usually applies a TAP block guided with ultrasound.

Standardize technique: critical view of the myopectineal orifice
The following are the steps to gain the critical view of the MPO, which are necessary to increase surgical success [9]   2. Rule out a direct hernia by visualizing the anatomy. Remove unusual fat in the Hesselbach's triangle.
3. Dissect the space of Retzius at least 2 cm between the CL and bladder to facilitate flat placement of the mesh.
4. Rule out a femoral hernia by dissecting between the CL and iliac vein.
5. Parietalize the cord's elements. To ensure compliance with this requirement, the dissection must continue until the cord's elements lie flat. Pull the sac and peritoneum upward; this maneuver will not trigger any movement of the cord's elements if this step is achieved.
7. Dissect the peritoneum lateral to the cord's elements beyond the anterior superior iliac spine.
8. Perform the dissection and ensure that mesh provides adequate coverage of all defects. Mechanical fixation must be placed above an imaginary inter-anterior superior iliac spine line and any defects to avoid recurrence and nerve injury.
9. Place the mesh only when items 1 to 8 are completed, and hemostasis has been verified. The mesh size should be at least 15-10 cm and be placed without creases or folds. Ensure that its lateral-inferior corner lies deep against the wall and does not roll up during space deflation.

eTEP technical features
The initial incision is made on the flank 3 cm above and 5 cm lateral to the umbilicus line [6,10,11]. See Figure 5 for unilateral hernia and Figure 6 for bilateral hernia trocar setup. At the selected location, a 12 mm incision is made, and the anterior fascia is exposed with the use of "S" retractors, the anterior fascia is incised with a no. 11 blade, the fibers of the rectal abdominis muscle are separate, and the posterior sheath is exposed. Blunt dissection with the finger is done, and the space created is lifted with the help of the "S" retractor to allow the introduction of the balloon dissector (Figure 7). Once the balloon dissector (Spacemaker™ Plus Dissector System) is inserted, the camera is introduced, and the balloon is inflated with the hand pump with 25-30 hand pumps of air under direct vision. The next step should follow the critical view of the myopectineal orifice [9].

TAPP technical features
The trocar setup we recommend is demonstrated in Figure 8; the initial incision is transumbilical [12,13], either Veress or Hasson technique can be done as the surgeons' preference, and a 12 mm trocar is introduced. After laparoscopy is done, two 5 mm trocar to the right and left of the umbilicus are introduced. Our recommendation for the peritoneal flap creation is to initiate the lateral side 2 cm upper and 2 cm medial to the anterior superior iliac spine. In a horizontal direction, it incises the peritoneum to the medial umbilical ligament (See Figure 1). The following dissection should be in a bloodless space, which could be done either in Zone 1 or in Zone 2 (See Figure 4). We recommend doing first the Zone 2 dissection because it is easier to identify the CL and the pubic tubercle (Figure 9). The next step should follow the critical view of the myopectineal orifice [9].

Pitfalls and pearls
• The TAPP technique is easier to learn and has a more "friendly" view of the anatomical landmarks than eTEP.
• The dissection of Zone 2 is easier to do and has a more consistent anatomy.
• The medial defect should be close if it is larger than 2 cm. We recommend the use of the European Hernia Classification to describe the hernias [14].
• The lateral hernia sac should be traction medially. Remember, "traction" and "counteraction" are the key steps to dissect the sac.
• "Twist" medially the sac to improve the traction. • The dissection of the cord's elements is achieved when we tract the peritoneal flap, and the movement is not transmitted to the cord's elements; the sac must reach the peritoneal flap.
• In larger sacs, the "ligation and section" approach is a valid option • If bleeding from the "Corona Mortis" occurs, simple compression with two or three gauzes is usually enough for 5 to 10 minutes. We do not recommend using electrocautery as it may tear the vessel or increase the zone of bleeding.
• The mesh should be at least 12 cm transversely and 11 cm vertically. We usually use a 14×14 cm mesh.
• We do not recommend using a pre-shaped mesh because it only increases the cost of the procedure. We use a polypropylene mesh of 15×15 cm (Ultrapro™ or Prolene™) and cut it to fix. We only cut the border of the mesh. See    absorbable stitches instead. Always remember not to apply it over the inferior epigastric vessels or beneath an imaginary line that runs transversely from the iliopubic tract to the pubic tubercle (See Figure 3). See Figure 12.
• Even though experts do not fix the mesh [15], we strongly recommend fixing it to diminish migration risk. On the other hand, the mesh's excessive fixation won't prevent a recurrence if the surgical technique isn't performed correctly and will increase the risk of postoperative pain and chronic pain [16].
• Tears can appear during the creation of the peritoneal flap, making it complicated to cover the mesh. Using the redundant peritoneal sac to cover the mesh with peritoneum is a feasible option.

Postoperative care
In the small or medium-sized hernias (L/M < 3), we managed the patient as an outpatient; during the learning curve, a 12-24 hours observation may be advisable.   The use of tight boxers and an icepack application in the groin region reduces postoperative pain and the inflammatory response. We recommend using the icepack for 30 minutes four times a day during the first seven days. Physical activity, mild activities (such as driving or going to work) are recommended after the 7th postoperative day; lifting over 10 kg or doing exercise is recommended after the 4th postoperative week.

Complications
Transoperative complications: the most common complication is peritoneal flap tear, which can be closed with the remanent sac or by diminishing the insufflator's pressure to do a primary closure. Bleeding of large vessels is a life-threatening complication. The more frequent injured vessels are the inferior epigastric vessels or the obturator vessels. If bleeding occurs, compression with gauze for