Our study showed that patients undergoing incisional hernia repair with existing coagulopathy, anticoagulant or antiplatelet therapy have a significantly higher postoperative surgical complication rate, postoperative bleeding rate, postoperative general complication rate, and mortality compared to patients without these pre-existing conditions. The risk of bleeding or of bleeding-related reoperation was significantly lower for the antiplatelet therapy subgroup than for the coagulopathy and anticoagulant therapy subgroups. Comparing open and laparoscopic IPOM approach, the postoperative bleeding rate was higher in open repair compared to laparoscopic IPOM repair, with significantly higher rates of postoperative bleeding in the HRG. Accordingly, the overall reoperation rate and bleeding-related reoperation rate were both significantly higher after open repair compared to laparoscopic repair. Since the registry does not record any information on this, the extent of dissection in laparoscopic IPOM cases is unknown. In particular, it remains unclear whether all connective and fatty tissues were removed from the “landing zone” in the region of the round ligament of liver (hepatic teres ligament) and the hepatic falciform ligament.
Another inherent weakness of a registry study is the fact that outcome criteria for bleeding seem very subjective. Bleeding on the skin or the volume of blood in the drain is not specified, nor is the person reporting this identified.
The multivariable analysis revealed other factors, which are significantly associated with an increased risk of postoperative bleeding, such as the use of drains, male gender, larger hernia defect size, and higher ASA score. Although there is a higher risk of bleeding in large defects, multivariable analysis shows an additional significant effect of the technique.
Furthermore, the reoperation rate due to bleeding-related complications as well as the reoperation rate due to other complications was significantly higher in the HRG compared to the NRG.
Postoperative bleeding and consecutive hematomas are bothersome for the patients and have a strong clinical impact requiring interventional or operative treatment [14]. Postoperative bleeding is a typical adverse event occurring after surgery [15]. Regarding inguinal hernia surgery alone, postoperative bleeding is the most frequent adverse event [16, 17]. A recent registry-based analysis of 82,911 patients undergoing open or endoscopic [transabdominal preperitoneal patch plasty (TAPP), total extraperitoneal patch plasty (TEP)] inguinal hernia repair showed a fourfold higher risk for onset of postoperative bleeding in patients with existing anticoagulation or antithrombotic therapy [10]. Surprisingly, the endoscopic procedures (TAPP, TEP) showed lower postoperative bleeding rates compared to open inguinal hernia repair, although the endoscopic techniques were deemed as being more likely to cause postoperative bleeding due to their more extensive tissue dissection. Additionally, larger hernia defect size, male gender, higher ASA score, and recurrent operation were identified as significant risk factors for postoperative bleeding in the registry population [10]. However, data on the risk of postoperative bleeding among patients undergoing incisional hernia repair are rare. Usually, incisional hernia repair is an elective procedure with carefully prepared patients. Since incisional hernias can present with larger defect sizes posing additional challenges, such as loss of domain, previous abdominal surgery or intraabdominal adhesions, prevention of postoperative bleeding necessitating reoperation seems to be of utmost importance. This is even more important in view of the fact that postoperative bleeding complications are deemed to be risk factors for recurrence after laparoscopic ventral hernia repair [18].
A recent study using a propensity score analysis of 486 consecutive patients undergoing incisional hernia repair revealed anticoagulation as a pre-existing condition frequently found in the risk group for postoperative bleeding, developing hematomas in 9.9% of open cases and 3.3% of laparoscopic IPOM cases [19]. In our study, however, we demonstrated that postoperative bleeding occurred in up to 3.9% of patients in the HRG of patients with coagulopathy, anticoagulant or antithrombotic therapy, leading to a significantly higher bleeding-related reoperation rate of 2.44% (n = 163) in the HRG compared to the NRG (0.98%). This demonstrates that coagulopathy, anticoagulant or antithrombotic therapy is an evident risk factor for postoperative bleeding requiring reoperation in a reasonable number of patients, with known unfavorable consequences such as prolonged hospital stays and increased direct and indirect healthcare costs.
The type of surgical approach in hernia surgery and its impact on postoperative complications are an ongoing debate. A recent analysis revealed substantial variation among hernia experts regarding decision-making in treatment strategies for incisional hernia patients [20], highlighting the difficulties in selecting the most appropriate surgical technique for the patient. Thus, it must be assumed that to date the choice of surgical technique in incisional hernia repair has been influenced more by the hernia parameters than by individual patient factors. Our study results demonstrate that the choice of surgical technique has significant impact on the postoperative outcome.
Apart from the surgical technique, a larger defect size, male gender, and higher ASA classification, intraoperative drains were identified as further risk factors for occurrence of postoperative bleeding. However, intraoperative drains must be viewed as a false-positive risk factor since drains themselves are unlikely to cause postoperative bleeding. It can be assumed that most surgeons usually place drains when they suspect possible postoperative bleeding, such as in high-risk patients.
Our data show that patients with abnormal INR or inadequate discontinuation of their antiplatelet or anticoagulation therapy undergoing incisional hernia repair are a high-risk population for onset of postoperative bleeding. Surgery for patients with these pre-existing conditions should be postponed or patients should be assigned to laparoscopic surgery when technically feasible and surgically meaningful, since laparoscopic IPOM repair has been shown to provide much more favorable outcomes compared to open repair. However, the advantages of the laparoscopic IPOM method should be carefully balanced against the described, technically inherent complications and the concerns arising from the emerging discussion of IPOM-related mesh complications in the abdominal cavity [21,22,23].