Postoperative haemorrhage following surgical repair of ventral incisional hernia

Clinical History

An elderly woman with history of hypertension, chronic cerebrovascular and systemic atherosclerosis, previous laparotomic left hemicolectomy for dysplastic sigmoid colon polyposis, suffered from acute abdominal pain with hard-consistency palpable swelling and severe blood loss (8 g/dl nadir haemoglobin) 24 hours after open surgical repair of midline incisional hernia (Rives procedure).

Imaging Findings

Ten days before laparoalloplasty, therapeutic anticoagulation was stopped and antithrombotic prophylaxis with low-molecular weight heparin was introduced.
The day after surgery, urgent multidetector CT including multiplanar reformations (Fig.1) confirmed the surgeon’s suspicion of iatrogenic haemorrhage, by effectively depicting a large (15x6x13 cm) hyperattenuating midline collection consistent with fresh postoperative anterior abdominal wall haematoma. The haematoma contained contrast extravasation foci indicating active arterial bleeding, and was located within the anterior abdominal subcutaneous fat and wall musculature, ventrally to the surgical site where the prosthetic mesh (thin and isodense to muscles) was poorly differentiated from parietal peritoneum and fascia transversalis. Minimal hemoperitoneum was associated.
Immediate relaparotomy confirmed bleeding suprafascial haematoma, which was attributed to persistent anticoagulation effect, and required haemostasis and surgical drainage.
The subsequent postoperative intensive care unit hospitalization ultimately resulted in patient’s recovery, but required several blood transfusions and was further complicated by haematoma reappearance (Fig.2) which was treated conservatively.

Discussion

Anterior abdominal wall hernias (including incisional hernias after any previous laparotomy) represent a common, challenging surgical problem and source of morbidity, including obstruction and strangulation if untreated. Indications for ventral hernia repair (VHR) include pain, cosmesis, and complications in descending order of frequency. Furthermore, large (>10 cm) asymptomatic hernias may require surgery [1, 2].
Nowadays standard-of-care VHR includes implantation of non-reabsorbable prosthetic mesh (PM) between the peritoneum and abdominal wall muscles over the defect to reduce tension at the hernia margins, and may be performed either during open surgery or, increasingly, laparoscopic surgery. Whereas in the past, recurrence rates approached 50%, the introduction of new biological materials dramatically changed hernia surgery so that effective VHR is currently achieved in the vast majority of patients, with low recurrence rates (3.4%-7.5%) and minimal perioperative morbidity. However, despite extensive surgical experience, open and laparoscopic VHR are associated with occasional serious short-term postoperative complications, mostly including seroma (2-11%), persistent pain (2-4.5%), ileus (2.2-8%) and wound infection (1.7%) [1-5].
Shortly after VHR, palpable swelling at the surgical site and unspecific complaints such as nausea, vomiting and abdominal pain are common, and surgeons may request urgent imaging to identify or rule out complications needing retreatment. Helpful in preoperative assessment of abdominal hernias, multidetector CT usefully complements physical examination in the diagnosis of postoperative complications as it shows recurrent hernias and abnormal collections with their exact size, relationship to the PM and anatomic structures of the anterior abdominal wall. However, CT interpretation is challenging without detailed knowledge of surgical procedure and familiarity with early postoperative imaging [2, 3, 5-7].
After VHR, CT visualization of the PM depends on its thickness and composition, whether of polypropylene (thin and isodense to muscles) or polytetrafluorethylene (hyperattenuating), and the presence or absence of surgical staples for fascia fixation. As this case exemplifies, CT allows prompt diagnosis of haematoma (heralded by unenhanced hyperattenuation) and active bleeding. Conversely, most collections observed at the operated abdominal wall ventral to the mesh are sterile seromas resulting from peritoneal fluid accumulation through porous PM in the potential space created by surgical manipulation. Seen at CT with fluid like attenuation, most seromas generally resolve without treatment within 6 weeks and do not require aspiration unless large or persistent. Peripheral enhancement may suggest superinfection or otherwise merely reflect recent surgical intervention [2, 3, 5-8].

Differential Diagnosis List

Final Diagnosis

Postoperative anterior abdominal wall haematoma following incisional hernia repair

URL:	https://www.eurorad.org/case/12330
DOI:	10.1594/EURORAD/CASE.12330
ISSN:	1563-4086