Perioperative management - Abdominal wall reconstruction according to Ramirez

The reconstruction of the abdominal wall in complex incisional hernias or the presence of a laparostoma presents a particular challenge. A "loss of domain" represents the extreme form of a volume displacement of the intestines.

Complex hernias are considered abdominal wall hernias with defect widths of more than 10 cm, incisional hernia recurrence after mesh implantation (mesh edge herniation, mesh tear, mesh rupture), hernias after flap transfer (denervation, donor site defects), and multiple recurrences.

The abdominal wall defect after laparostoma represents a special situation. An abdominal wall closure has never occurred here. Complicating matters, there is no natural skin in the area of the abdominal wall defect, but rather a split-thickness skin graft. There is also no hernia sac helpful for reconstruction. The closure of the skin can present an additional problem.

In principle, the indication for repair of even a complex hernia is given. The patients lack ventral stabilizing elements of the trunk musculature. Patients with such unstable abdominal walls complain of postural problems with back pain. Physically demanding activities and sports are severely restricted to impossible. An intact ventral abdominal wall is of great importance for physiological processes such as breathing and defecation.

Furthermore, the abdominal wall defect and the extra-abdominal organ volume will continue to increase. The reconstruction of the abdominal wall is ultimately carried out to prevent increasing morbidity.

To achieve a fascial closure in the midline in these hernias, an abdominal wall component separation is usually required.

With the anterior component separation ("Ramirez") presented here, midline defects with a width of periumbilical up to 20 cm, epigastric up to 8 cm, and suprapubic up to 6 cm in diameter can be closed by separating parts of the lateral abdominal wall. The technique allows for a tension-free closure with a dynamically competent abdominal wall.

Due to the broad detachment of the subcutaneous tissue with the risk of destroying perforating vessels (blood supply to subcutaneous tissue and skin by the deep epigastric vessels) and the resulting high rate of wound healing disorders, hematomas, and seromas, this technique is now considered only a second-choice procedure. The posterior component separation, which leads to a release in the area of the M. transversus, is favored; additionally, the mesh bed can be expanded laterally, dorsally, and retrocostally.

The reconstruction according to Ramirez was described in the original work without mesh augmentation. The results in the literature favor the simultaneous implantation of a retromuscular mesh.

In the demonstrated case, as a special feature, in the absence of material for the closure of the peritoneum or the posterior rectus sheath, a defect bridging with the introduction of a biological mesh is shown. Alternatively, an IPOM-capable synthetic mesh can also be used. The advantage of a biological mesh is the possibility of application in an infected surgical field, better stretchability, and the natural remodeling into the body's own tissue.

The introduction of botulinum toxin for the relaxation of the lateral abdominal wall musculature has significantly reduced the necessity of component separation in midline hernias.

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 due to the risk of uncontrollable bleeding from abdominal wall vessels.
It is also important to ensure a good respiratory condition that is not compromised by acute infections. In the presence of respiratory infections, elective surgery must be postponed.

• The abdominal wall hernia is a clinical diagnosis and can be well recognized in a standing patient. It is advisable to also 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.
• To determine the defect location, the extent of the defect, and to depict the abdominal wall anatomy, CT is the best diagnostic procedure, alternatively an MRI.
• In cases of previous incisional hernia repairs, a corresponding surgical report is often helpful, especially if a mesh repair has already been performed. Here, in addition to the exact surgical technique (extra- or intraperitoneal mesh placement, augmentation or bridging of the fascial defect), the type of mesh material is particularly important.
• In extensive findings, thorough cardiopulmonary function diagnostics are recommended due to the increase in pressure after repositioning the protruded intestines.

For better characterization of 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 subxiphoidal, 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 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
• Bowel evacuation is advisable, preoperative bowel lavage is not strictly necessary.
• 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.

The most important preparation is the assessment of the possibility of repositioning prolapsed organs. In advanced eventration of the intestines, additional conditioning of the abdominal wall is recommended. The following options exist:

• progressive pneumoperitoneum: Stretching of the abdominal wall by insufflation of air through a catheter into the abdomen. Central venous catheters, small pleural catheters, or similar are used, as no standardized instruments exist. This catheter is pulled through the abdominal wall in a primary procedure. The catheters should be equipped with a bacterial filter and a closure system. Depending on the scheme, room air is applied daily into the abdomen using a large-bore syringe. Preoperative hospitalization of the patient is a disadvantage.
• Injection of botulinum toxin into the lateral abdominal muscles 4 weeks preoperatively.
• Intraoperative fascial traction, where the lateral abdominal muscles are mechanically stretched intraoperatively, traction duration 30 min with 14 - 20 kg.
• An average length gain of 4 - 5 cm per side is indicated for all methods.

In the example, conditioning is performed using pneumoperitoneum

General:

• Pneumonia
• Bleeding, rebleeding, hematoma
• Wound infection/wound healing disorder
• Thrombosis/embolism
• Excessive scar formation
• Injuries to adjacent structures such as nerves, vessels, bladder, and bowel

Specific:

• Implantation of synthetic material
• Reduced load-bearing capacity, especially during the first 3 months
• Altered shape of the abdominal wall, depressions due to lack of subcutaneous tissue
• Abdominal wall paralysis
• Nerve injury/chronic pain
• Seroma (usually present, mostly 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

• Anesthesia is generally performed under general anesthesia ITN.
• Pain management is carried out using PDK.

• Position the patient in a supine position, right arm positioned alongside.
• Slight hyperextension of the patient during preparation, or neutral position during fascial closure.

• The surgeon initially stands to the right of the patient and switches to the opposite side after preparing the left side to be able to prepare the right side without difficulty.
• The first assistant stands opposite the surgeon.
• The optional second assistant stands to the right of the first assistant.
• The instrument nurse stands to the right of the patient next to the surgeon and also switches to the opposite side.

• Biological mesh or IPOM mesh as implant
• Redon drains CH12 and CH14

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

medical follow-up treatment:

• Postoperative monitoring in an intensive care unit or intermediate care unit
• Single-shot antibiotic therapy in contaminated or infected conditions, prolong according to antibiogram if necessary.
• After umbilical, incisional, or upper abdominal hernias with mesh placement, consistent wearing of an abdominal binder for 4 - 6 weeks is recommended. This is intended to prevent seroma and promote better and faster integration of the mesh. There is no clear data on this.
• Redon drains are removed when the drainage output is < 10 - 20 ml/day.
• Maintenance of basic mobility and light physical activity. Avoid 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 > 30 minutes duration), low molecular weight heparin should be administered in prophylactic, possibly weight- or disposition risk-adapted dosage until full mobilization is achieved.
Note: Renal function, HIT II (history, platelet control)
Follow the link to the current guideline: Prophylaxis of venous thromboembolism (VTE).

mobilization: Immediate

physical therapy: Intensive respiratory therapy for large hernias or older patients

dietary progression: Immediate

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

incapacity for work: Depending on the extent of the condition, 3 - 4 weeks. For occupations with heavy abdominal wall strain → Avoid carrying/lifting heavy loads, possibly up to 12 weeks.