Perioperative management - Incisional hernia repair with open, retromuscular mesh augmentation

According to the guidelines of the EHS and AHS, the open sublay technique is an option for the treatment of primary and secondary abdominal wall hernias with defects between 4 and 10 cm.

With a retromuscular mesh positioning behind the rectus abdominis muscle, this technique is particularly suitable for midline defects.

In the situation of incarceration, depending on the degree of contamination, treatment with a synthetic mesh is indicated only with great caution.

The demonstration of the retromuscular layer as an optimal mesh bed has led to a renaissance of the open sublay procedure in incisional hernia surgery in recent years.

The sublay technique describes a retromuscular preperitoneal position of the mesh, ideally involving a midline reconstruction with closure of the fascia over the mesh. This achieves a good mesh support, with the intra-abdominal pressure on the mesh acting as the strongest component of the closure and supporting its fixation.

In principle, the indication for the repair of an abdominal wall hernia is always given, as the hernia gap and extra-abdominal organ volume will usually continue to enlarge. In larger defects, ventral stabilizing elements of the trunk musculature are lacking. Physically demanding activities and sports may be severely restricted to impossible.

The only exception is an incidental finding in the context of cross-sectional imaging for other reasons. In the absence of symptoms, there is not necessarily an indication for surgery.

For elective procedures, infection-free skin conditions are mandatory; pressure ulcers and superficial skin infections should initially be treated conservatively. The indication for hernia repair in patients with liver cirrhosis and ascites should be critically evaluated, and preoperative optimization of liver function should be considered if necessary. In cases of severe coagulation disorders (Quick < 50%, PTT > 60 s, platelets < 50 /nl) and pronounced portal hypertension with caput medusae, surgery should be avoided, particularly due to the risk of uncontrollable bleeding from abdominal wall vessels. It is also important to ensure a good respiratory situation that is not compromised by acute infections. In the presence of respiratory infections, an elective procedure must be postponed.

An abdominal wall hernia is a clinical diagnosis and can often be easily recognized in a standing patient. It is advisable to additionally examine the patient in a relaxed, lying position. When the patient is asked to lift the upper body, the fascial edge, the extent of the fascial defect, and the surrounding muscles can usually be assessed in reducible incisional hernias.

For smaller primary hernias, abdominal ultrasonography is a significant imaging modality.

To determine the defect location and extent, especially in incisional hernias, and to depict the abdominal wall anatomy, CT is the best diagnostic procedure, alternatively an MRI.

For previous incisional hernia repairs, a corresponding surgical report is often helpful, especially if a mesh repair has already been performed. Here, besides the exact surgical technique (extra- or intraperitoneal mesh placement, augmentation, or bridging of the fascial defect), the type of mesh material is also important.

In extensive findings, thorough cardiopulmonary function diagnostics are recommended due to the increase in pressure after repositioning the protruded viscera.

To better characterize the present hernia, the EHS classification should be used.

Classification of primary ventral hernias

Classification of secondary ventral hernias (incisional hernias)

The classification of secondary abdominal wall hernias is initially based on a medial or lateral defect location in the abdominal wall.

The defect location of medial hernias is then more precisely delineated as subxiphoid, epigastric, umbilical, infraumbilical, and suprapubic. Laterally, the defects are classified as subcostal, lateral, iliac, and lumbar.

Further consideration is given to the defect width of incisional hernias: W1 (< 4 cm), W2 (4 - 10 cm), and W3 (> 10 cm).

If multiple hernia defects exist (mesh-related hernia, Swiss-cheese hernia), their size is determined by the total length and width.

• Control of infection situations
• Medication management in immunosuppression or anticoagulation
• Control of cardiac and pulmonary risk factors
• In advanced eventration of the intestines, conditioning of the abdominal wall through progressive pneumoperitoneum or injection of botulinum toxin into the lateral abdominal muscles.
• Bowel evacuation is advisable, preoperative bowel lavage is not required.
• Single-shot antibiotic i.v. perioperatively (due to the use of foreign material/mesh), continuation of therapy if there are intraoperative signs of inflammation or bacterial contamination.

General:

• Pneumonia
• Bleeding, rebleeding, hematoma
• Wound infection/wound healing disorder
• Thrombosis/embolism
• Excessive scar formation

Specific:

• Implantation of synthetic material
• Nerve injury/chronic pain
• Seroma (typically present, usually without therapeutic consequence)
• Infection of the implant with the consequence of needing to remove it again.
• Bowel passage disorder (atony/ileus)
• Recurrent hernia
• Bowel perforation
• Subsequent interventions
• Lethality

• Due to the complex anatomical preparation in retromuscular mesh augmentation, this procedure is performed under intubation anesthesia.
• The placement of an epidural catheter (EDC) has proven advantageous, especially for the postoperative course regarding analgesia.

• Supine position, possibly with one arm adducted.
• Depending on the size of the finding, slight hyperextension of the patient during preparation, or neutral position during fascial closure.

Typically, the operation begins with the surgeon standing on the right, opposite the first assistant, with the instrument nurse to the left of the assistant. In this setup, the preparation of the left mesh bed, i.e., on the assistant's side, is initially performed. Depending on the intraoperative view, it may be advantageous for the surgeon and the first assistant to switch positions to prepare the opposite side.

Additional materials:
Implants: non-resorbable, large-pore, surface-reduced meshes, e.g., made of polypropylene, polyester, PVDF

Postoperative analgesia: Non-steroidal anti-inflammatory drugs are generally sufficient; if necessary, an increase with opioid-containing analgesics can be made. Follow the link here to PROSPECT (Procedures Specific Postoperative Pain Management). Follow the link here to the current guideline: Treatment of acute perioperative and post-traumatic pain.

Medical follow-up treatment: After umbilical, incisional, or upper abdominal hernias with mesh placement, the consistent wearing of an abdominal binder for 4-6 weeks is recommended. This is intended to prevent a seroma and promote better and faster integration of the mesh. There is no clear data on this.

Redon drains are removed when the output is < 10-20 ml/day. Inform the patient about reduced resilience, especially during the first 3 months!

Maintenance of basic mobility and light physical activity. Avoidance of sports and lifting loads for up to 3 months. Inpatient rehabilitation depending on age, mobility, and home care.

Thrombosis prophylaxis: In the absence of contraindications, due to the moderate thromboembolic risk (surgical procedure > 30min duration), low molecular weight heparin should be administered in prophylactic, possibly weight- or disposition risk-adapted dosing until full mobilization is achieved. Note: Renal function, HIT II (history, platelet control) Follow the link here to the current guideline: Prophylaxis of venous thromboembolism (VTE).

Mobilization: Immediate

Physical therapy: For large hernias or older patients, intensive respiratory therapy

Dietary progression: Immediate

Bowel regulation: If necessary, oral laxatives from the 3rd/4th day to prevent postoperative intestinal atony; constipation should also be avoided in the long term.

Incapacity for work: Depending on the extent of the findings, 3 - 4 weeks. In professions with heavy abdominal wall strain → Avoid carrying/lifting heavy loads, possibly up to 6 - 12 weeks.