What are the differences between Transabdominal Preperitoneal (TAPP) and Totally Extraperitoneal (TEP) inguinal hernia repair?

TAPP and TEP Inguinal Hernia Repair: Laparoscopic Techniques

TAPP (Transabdominal Preperitoneal) and TEP (Totally Extraperitoneal) are the two primary laparoscopic approaches for inguinal hernia repair, both involving mesh placement in the preperitoneal space, with TAPP requiring entry into the abdominal cavity while TEP avoids it entirely. 1, 2

Technical Differences Between TAPP and TEP

TAPP Technique

• Requires entering the peritoneal cavity to create a peritoneal flap, then placing mesh in the preperitoneal space before closing the peritoneum 3
• Allows direct visualization of the abdominal cavity and contralateral side 2, 4
• Permits identification of occult contralateral hernias, present in 11.2-50% of cases 1, 2, 4
• May be technically easier in recurrent hernias due to better visualization of distorted anatomy 3
• Preferred after previous lower abdominal surgery where TEP may be more challenging 3

TEP Technique

• Performed entirely in the extraperitoneal space without entering the abdominal cavity 5
• Avoids potential intra-abdominal complications by staying outside the peritoneal lining 5
• Requires a steeper learning curve for surgeons 5
• Associated with shorter hospital stay in primary hernia cases (mean difference -0.87 days) 6

Clinical Outcomes: TAPP vs TEP

Equivalent Outcomes

The evidence demonstrates no clinically significant differences between TAPP and TEP for most critical outcomes:

• Serious adverse events: 0.4% (TAPP) vs 0.7% (TEP), with no significant difference 5
• Hernia recurrence rates: 1.2% (TAPP) vs 1.1% (TEP), essentially equivalent 5
• Chronic pain (≥6 months): No significant difference between techniques 5
• Postoperative complications: Similar rates of seroma/hematoma formation 7, 5
• Time to return to work: Comparable between both approaches 8, 6
• Quality of life: Little to no difference in late postoperative phase 5

Differences Favoring TAPP

• Less postoperative pain at 6 hours, 24 hours, and 7 days compared to TEP 7
• Lower analgesic requirements, though not statistically significant 7
• Lower conversion rate to open surgery: 0.7% (TAPP) vs 2.5% (TEP) 5
• Shorter operative time for recurrent hernias 6

Differences Favoring TEP

• Shorter hospital stay for primary hernias (approximately 0.87 days less) 6
• Avoids entering the abdominal cavity, theoretically reducing visceral injury risk 5
• Shorter operative time for primary hernias 7, 6

Clinical Application Algorithm

For Uncomplicated Primary Inguinal Hernias

Either TAPP or TEP is appropriate, with choice based on:

• Surgeon experience and preference 8, 5
• Patient desire for potentially shorter hospital stay (favor TEP) 6
• Concern about contralateral occult hernia (favor TAPP for bilateral visualization) 2, 4

For Recurrent Hernias

TAPP may be preferred due to better visualization of distorted anatomy from previous repair 3

For Bilateral Hernias

Both techniques are suitable, though TAPP allows simultaneous visualization of both sides 2

For Incarcerated Hernias Without Strangulation

Both TAPP and TEP can be used to assess bowel viability and perform repair 1, 3

• Laparoscopic approach shows significantly lower wound infection rates (P<0.018) compared to open repair 1, 2
• No increase in recurrence rates versus open approach 1, 2

For Strangulated Hernias or Suspected Bowel Compromise

Open preperitoneal approach is preferable when bowel resection may be needed 1, 3

• Local anesthesia can be used for incarcerated inguinal hernias without bowel gangrene 1, 4

Common Pitfalls and Caveats

Conversion Risk

• TEP has higher conversion rates (2.5% vs 0.7% for TAPP) to either TAPP or open surgery 5
• Surgeons choosing TEP should have proficiency in TAPP technique or be prepared for open conversion 5
• Patients should be counseled preoperatively about conversion risk 5

Learning Curve Considerations

• TEP requires steeper learning curve than TAPP 5
• Surgeons early in their laparoscopic hernia experience may find TAPP more accessible 5

Emergency Settings

• Do not delay repair of strangulated hernias, as this increases morbidity and mortality 2
• Diagnostic laparoscopy (hernioscopy) can assess bowel viability after spontaneous reduction 1, 2
• In unstable patients with severe sepsis, open management is recommended 4

Mesh Considerations

• Synthetic mesh is standard for both techniques in clean surgical fields 2, 4
• Mesh repair shows significantly lower recurrence rates (0% vs 19% with tissue repair) 2
• For contaminated fields with bowel necrosis, biological mesh or primary repair may be needed 4

Practical Decision-Making

The choice between TAPP and TEP should reflect surgeon expertise and patient-specific factors, as both techniques demonstrate equivalent efficacy for the most important outcomes: serious adverse events, recurrence, and chronic pain 8, 5. The slightly higher conversion rate with TEP (2.5% vs 0.7%) suggests that surgeons should either maintain proficiency in both techniques or have a clear conversion strategy 5.