Hernia Inguinal Repair, Laparoscopic
The surgical history of inguinal hernias dates back to ancient Egypt. From Bassini’s heralding of the modern era to today’s mesh-based open and laparoscopic repairs, this history parallels closely the evolution in anatomical understanding and development of the techniques of general surgery.
Accounting for 75% of all abdominal wall hernias, and with a lifetime risk of 27% in men and 3% in women, inguinal hernia repair is one of the most commonly performed surgeries in the world. In the United States, inguinal herniorrhaphy accounts for approximately 800,000 cases annually.
Most randomized studies comparing laparoscopy to open repair have confirmed the following findings.
- Earlier return to work
- Reduced postoperative pain
- Lengthier operation
- Increased cost
- Steeper learning curve
- Higher recurrence and complication rates early in a surgeon's experience
Although open, mesh-based, tension-free repair remains the criterion standard, laparoscopic herniorrhaphy, in the hands of adequately trained surgeons, produces excellent results comparable to those of open repair.
Laparoscopic inguinal herniorrhaphy can refer to any of the following 3 techniques:
- Totally extraperitoneal (TEP)
- Transabdominal preperitoneal (TAPP) repair: The abdomen is accessed and pneumoperitoneum is achieved using standard laparoscopic techniques. The preperitoneal space is then exposed transabdominally by sharply incising and bluntly stripping the peritoneum that overlies the inguinal anatomy. A mesh is then deployed and fixed in place as with the TEP technique and the peritoneum returned to its anatomical position.
- Intraperitoneal onlay mesh (IPOM) repair: A dual-layer mesh is placed over the myopectineal orifice transabdominally and fixed in place. The preperitoneal space is not entered and minimal dissection is carried out.
- The most commonly performed laparoscopic techniques are the TEP and TAPP repairs.
Poor familiarity with the complex anatomy of the posterior inguinal view is an important contributor to the steepness of the laparoscopic inguinal herniorrhaphy learning curve.
The preperitoneal space is contained between the transversalis fascia and the parietal peritoneum. It contains areola and adipose tissue and the inferior epigastric artery and vein.
Transabdominal laparoscopic landmarks useful when performing the TAPP repair are the obliterated fetal remnants, which divide the posterior surface of the anterior abdominal wall into 3 fossae.
- The median umbilical ligament is a remnant of the embryonic urachus. It forms the center divider by arising in the midline from the apex of the bladder toward the umbilicus.
- Laterally, the paired medial umbilical ligaments, vestiges of the fetal umbilical arteries, arise from the superior vesicle arteries toward the umbilicus.
- Between the median and medial ligaments lie the supravesical fossae, where external supravesical hernias occur.
- Most lateral are the paired lateral umbilical ligaments, which contain the inferior epigastric arteries. Between them and the medial ligaments lies the medial fossa, which contains the Hesselbach triangle, the zone of direct hernias. Lateral to the inferior epigastric arteries is the lateral fossa, which is the site of indirect hernias. Thus, the lateral umbilical ligaments separate the lateral and medial fossae, and delineate between indirect and direct hernias, respectively.
Inguinal anatomy from the laparoscopic viewpoint:
- The inferior epigastric artery and vein complex: This complex lies on the rectus muscles bilaterally.
- Medial to these vessels but above the iliopubic tract is the external ring, which is not visible in patients without a direct hernia.
- The internal ring is lateral to the inferior epigastric artery and vein but is often obscured by them, even when a hernia is present. The location of the internal ring can be approximated by locating the junction of these vessels and the cord structures.
- The femoral ring is inferior and lateral to the external ring and lies below the iliopubic tract just medial to the external iliac vessels. (The external iliac vessels change their name to the common femoral vessels after they pass beyond the inguinal ligament. Since preperitoneal hernia repair is performed dorsal to the inguinal ligament, these vessels still retain their intra-abdominal name.)
- Cooper ligament: This is the name given to the periosteum of the superior pubic ramus. The pubic ramus can be easily palpated with a blunt grasper and is an excellent starting point for dissection.
- Iliopubic tract: Another fundamental structure that deserves careful recognition is the iliopubic tract (commonly referred to as the shelving edge of the inguinal ligament in open surgery).
- This aponeurotic stretch of tissue is located posterior to the inguinal ligament and extends from the anterior superior iliac spine to the superior pubic ramus. As a continuation of the transverse abdominus aponeurosis and fascia at the upper border of the femoral sheath, it passes medially to form the inferior border of the internal inguinal ring, crossing over the femoral vessels.
- Importantly, the iliopubic tract forms the superolateral border of the so-called "triangle of pain," an area bounded medially by the spermatic vessels. In this area, tacking of the mesh is to be avoided because of the risk of injury to the femoral branch of the genitofemoral nerve or the lateral femoral cutaneous nerve.
Triangle of pain:
Another anatomical zone that requires the surgeon’s awareness is the so-called "triangle of doom," bordered medially by the ductus deferens, laterally by the spermatic vessels, and with its apex at the deep inguinal ring. This area contains the external iliac artery and vein; thus, tacking of the mesh must be avoided within its boundaries.
- The general indications for laparoscopic inguinal hernia repair versus watchful waiting are the same as for open inguinal hernia repair.
- Classically, the existence of an inguinal hernia has been reason enough for operative intervention. However, recent studies have shown that the presence of a reducible hernia is not, in itself, an indication for surgery and that the risk of incarceration is less than 1%.
- Symptomatic patients (with pain or discomfort) should undergo repair; however, up to one third of patients with inguinal hernias are asymptomatic. The question of observation versus surgical intervention in this asymptomatic or minimally symptomatic population was recently addressed in 2 randomized clinical trials. The trials found similar results, namely that after long-term follow-up, no significant difference in hernia-related symptomology was noted, and that watchful waiting did not increase the complication rate.
- In one study, the substantial patient crossover from the observation group to the surgery arm may delay but not prevent surgery. This reasoning holds particularly true in the younger patient population. Thus, even an asymptomatic patient, if medically fit, should be offered surgical repair.
- Some reports have listed specific indications for laparoscopy over open repair, including recurrent hernias, bilateral hernias, and the need for earlier return to full activities.
- Patient preference plays perhaps the greatest role in choosing one type of repair over another.
- Surgical expertise also plays a role in selecting the appropriate type of repair. Data show that the recurrence rate drops significantly with increased surgeon experience with the laparoscopic technique. Some studies suggest that the learning curve for totally extraperitoneal (TEP) laparoscopic herniorrhaphy may be as high as 250 cases (as opposed to 25 for open repair). Transabdominal preperitoneal (TAPP) repair has a learning curve closer to that of the open technique. A large randomized controlled trial comparing laparoscopic to open repair found that, with adequate training, laparoscopic repair produced equivalent recurrence rates but reduced postoperative pain and allowed earlier return to work.
- A Cochrane database meta-analysis comparing TEP to TAPP found no significant difference in recurrence but did find that TAPP was associated with a higher risk of intra-abdominal injury.
- The intraperitoneal onlay mesh (IPOM) technique has fallen out of favor because of reports of unacceptably high rates of organ injury, nerve injury, and hernia recurrence.
- Conclusions regarding inguinal hernias in female patients are difficult to draw because most of the inguinal hernia literature involves male patients. In fact, recurrence rates were higher in women and that recurrence in women was 10 times more likely to be of the femoral variety than in men. This has led some to the conclusion that repairs that provide coverage of the femoral space (e.g., laparoscopic repair) at the time of initial operation are better suited for women as a primary repair.
- The actual hospital costs of laparoscopic repairs are higher than those of open repairs but may be offset by the societal benefits of earlier return to full activities.
- General contraindications for laparoscopic herniorrhaphy parallel those of open repair.
- Inguinal hernia repair has no absolute contraindications. Just as in any other elective surgical procedure, the patient must be medically optimized. Any medical issues, whether acute (e.g., upper respiratory tract or skin infection) or exacerbations of underlying medical conditions (e.g., poorly controlled diabetes mellitus), should be fully addressed and the surgery delayed accordingly.
- Patients with elevated American Society of Anesthesiologists (ASA) scores and high operative risk should undergo a full preoperative workup and determination of the risk-to-benefit ratio.
- Contraindications specific to the laparoscopic technique include a lower midline incision, previous preperitoneal surgery (e.g., prostatectomy), irreducible hernia, and inability to tolerate general anesthesia