Complications - Incisional hernia repair, Dynamesh® – IPOM

• Intraoperative Bleeding
  
  During transfacial fixation, care must be taken to avoid injury to abdominal wall vessels, particularly the epigastric vessels. In the case of persistent bleeding due to staplers, a transperitoneal suture with a suture passer is recommended.
   
• Bowel Injury During Adhesiolysis
  
  Deserosations must be identified and immediately oversewn.
  
  For transmural lesions, the location (small intestine - large intestine) and the amount of bowel content leakage are crucial; if necessary, postpone the mesh implantation for 4 - 7 days.
  
  In the case of massive stool leakage, conversion should be considered.

• Postoperative Bleeding/Hematoma/Pneumothorax
  
  Ultrasound monitoring, with possible aspiration if size progresses. Hemoglobin-relevant bleeding and large symptomatic hematomas must be revised. Avoid using staples on the diaphragm as cardiac tamponades and pneumothoraces with fatal outcomes have been reported. Alternatively, biological adhesives can be used.
   
• Unnoticed Secondary Bowel Perforation
  
  If the expected postoperative course deviates and there is suspicion of an unnoticed bowel lesion (fever, peritonitis, ileus, infection parameters), surgical exploration is necessary. Reoperation with detection of the bowel lesion and suturing, possibly resection and abdominal lavage, antibiotic treatment, possibly mesh explantation. Mortality approximately 3%.
  
  Adhesiolysis should preferably be performed only with scissors. Monopolar current can be applied selectively, and ultrasound scissors should be completely avoided due to unnoticed thermal damage.
  
  Unnoticed bowel lesions are possible not only during adhesiolysis but also during primary access through bowel puncture.
   
• Postoperative Bowel Paralysis/Manifest Ileus
  
  Bowel paralysis after extensive adhesiolysis or bowel wall suturing is common. A slow dietary build-up is recommended, possibly with antiemetic medication to prevent retching and vomiting. Conservative bowel stimulation, possibly with a prokinetic agent (e.g., neostigmine), can be useful; in the case of manifest ileus, reoperation with detection and correction of the cause.
   
• Acute/Chronic Postoperative Pain

Acute postoperative pain is most likely due to extensive manipulation of the parietal peritoneum or the pneumoperitoneum itself.

Chronic postoperative pain was defined in 1986 by the "International Association for the Study of Pain" as pain persisting for more than three months despite optimal conservative therapy.

Possible causes include traumatic nerve damage from suturing during mesh fixation, especially with non-absorbable suture material, or nerve entrapment in tacks.

Consistent postoperative analgesia. For therapy-resistant pain localized to a trans-fascial retention suture, this should be removed through a circumscribed approach. Identification of segmental spread and attempt at segmental blockade, possibly neurectomy of the affected intercostal nerve. Mesh removal as a last resort.

Risk factors include pre-existing or poorly controlled early postoperative pain, female gender, and a defect width > 10 cm.
 

• Seroma
  
  A seroma is regularly present depending on the size of the hernia sac and without therapeutic consequence, possibly with ultrasound follow-up. If the size of the seroma leads to clinical symptoms, puncture (absolutely sterile!) can be performed in individual cases (possibly with microbiological examination). For recurrent seromas, repeated puncture should be avoided; instead, ultrasound-controlled drainage should be inserted and consistently drained for several days. Caution: Each puncture increases the risk of mesh infection.
   
• Mesh Infection
  
  A true mesh infection is very rare and manifests as peritonitis. In contaminated conditions, the risk of a mesh infection is significantly increased. Postoperative peritonitis is usually caused by an unnoticed bowel lesion, necessitating revision. In the case of manifest peritonitis, the mesh must be removed. In moderate or localized peritonitis without clinical sepsis, a conservative attempt is justified. If the situation does not improve over the next 2 - 3 days, mesh removal is indicated.
   
• Pseudorecurrence/Bulging
  
  Apart from a seroma or hematoma, which is perceived similarly to preoperative symptoms, especially due to swelling, bulging can occur in up to 17% of large hernias. This involves the early postoperative protrusion of the mesh through the large defect without an actual hernia due to the lack of abdominal wall reconstruction.
   
• Recurrence approximately 10 - 15%
  
  Risk factors include a hernia diameter of > 5 cm, intra-abdominal obesity, and lateral defect location.
  
  In IPOM, recurrence typically occurs at the edge due to insufficient overlap or mesh shrinkage.
  
  In clinically irrelevant recurrence with no symptoms, usually found incidentally during imaging for other reasons, there is only a limited indication for surgery. If size progression or symptoms occur, reoperation should be considered.
   
• Adhesions/Mesh Migration/Bowel Fistula
  
  Direct contact of the mesh implant with the abdominal cavity can lead to adhesions to the bowel, in rare cases with mesh migration and formation of enteric fistulas.
  
  In most cases, adhesions remain without consequence as long as direct contact of the bowel with polypropylene is avoided. An intraperitoneal position of a polypropylene prosthesis leads to the need for bowel resection in more than 20% of cases.
   
•  Worsening of Portal Hypertension
  
  In the area of the falciform ligament, only very critical transection of venous collateral circulations should be performed; if only an open umbilical vein is present, it can be clipped.