FD after RC is a dreaded complication requiring improved characterization and management guidance. Our multicenter study shows that a significant percentage of concomitant intraabdominal pathologies were identified only at the time of dehiscence repair. These findings highlight the need for thorough abdominal exploration and prompt diagnosis to prevent additional morbidity.

FD was previously found to occur in up to 9% of RC [5]. However, more contemporary series reported a rate of 3% [7, 13], similar to our results. Identification of risk factors and preventive measures may have contributed to the reduced rate of FD. Potentially modifiable risk factors include patient-related factors, such as preoperative malnutrition, smoking, body mass index ≥ 25, postoperative coughing, and technical errors during wound closure [10, 17]. Despite efforts to control preoperative, intraoperative, and postoperative factors, the majority of patients will require surgical repair once FD occurs [14].

Although the fastest and simplest surgical intervention to repair FD is by primary closure of the fascial edges, FD might be accompanied by intraabdominal pathologies [17]. While these complications may serve as potential predisposing factors for FD, they are not always clinically evident. In our cohort, accompanying complications were identified in a quarter of patients only at the time of fascial repair. Most findings were anastomotic leaks that were amenable to primary repair. Indeed, the surgical complexity of RC is related to the urinary-gastrointestinal anastomoses, usually performed in patients with comorbid conditions that may increase the risk for anastomotic breakdown.

FD was diagnosed and repaired after a median time of 7 days following cystectomy, similar to previous reports, and around the time of the susceptible proliferative and remodeling phases of wound repair [8, 9, 13, 14, 18]. Interestingly, patients with accompanying intraabdominal findings were diagnosed with FD three days later than the rest. While the reason for that is not apparent, it is possible that in patients with intraabdominal pathologies the mechanism and course of FD development differs from that of patients without intraabdominal pathologies.

While abdominal imaging is not routinely performed before FD repair, two of our cohort's seven patients who had accompanying intraabdominal pathologies underwent a contrast CT to support FD diagnosis. However, the urography phase was not included in these CT scans, and the urinary leaks went undiagnosed. Therefore, if the decision to perform a CT is made, the urography phase should be included.

The only clinical factor found to predict the accompanying pathologies was IHD. Atherosclerosis leads to tissue hypoperfusion, decreased oxygenation, and impaired tissue healing. Therefore, it is reasonable that patients with IHD will be at an increased risk for wound complications and anastomotic breakdown, causing urine or fecal leak.

Although hospital stay was longer among patients with accompanying intraabdominal pathologies, the rate of post-exploration complications was similar in these patients compared to patients who only had FD. Identifying these pathologies and their primary repair during the abdominal exploration might have prevented additional adverse outcomes. Nevertheless, it should be mentioned that during the abdominal exploration, iatrogenic injury to the ileo-ileal anastomosis occurred in one patient, which was primarily sutured without further complications.

This study's overall 30-day mortality rate was 11%, higher than the 2–3% reported for general RC series [3, 4]. There was no association between mortality and accompanying intrabdominal pathologies. This high mortality rate probably reflects a significantly increased surgical risk in the FD population. Patients in this study were older and sicker than those in previous studies (median Charlson comorbidity index = 6) [4, 14], two parameters that are associated with post-RC mortality [19]. Similarly, high mortality rates of up to 45% have been reported in patients who experienced FD after colorectal surgeries [9, 10].

Late complications after FD repair are not uncommon. They are associated with additional physical and mental burdens and further increase the cost of care [11, 17]. For example, an incisional hernia carries the risk of subsequent bowel obstruction and the need for additional procedures. In our study, accompanying intraabdominal pathologies did not increase the risk for late complications and did not impact overall survival. It is reasonable to assume that identifying and correcting these pathologies assisted in preventing further sequelae.

Our study is limited by its retrospective design and small sample size. The lack of standardized diagnostic evaluation before the surgical intervention may have impacted our findings. Specifically, some of the surgical findings would have been identified by contrast CT scan with urography phase performed prior to FD repair.

Furthermore, our data was collected from several tertiary referral centers, and the studied event is relatively uncommon, precluding other study types. The lack of a control group might hamper our assumption that the primary correction of accompanying intraabdominal findings prevented further consequences. However, even if some of the complications would have resolved spontaneously, further delay in diagnosing severe complications, such as bowel leak, could have led to life-threatening clinical deterioration. We have also shown that the clinical benefit appears to overcome the potential risk of surgical exploration. There was a single case of iatrogenic injury, amendable for immediate repair. Eventually, long-term morbidity and mortality were not higher in patients with accompanying intraabdominal pathologies.

Our results shed light on the prevalence, management, and outcomes of adverse intraabdominal findings during FD repair post-RC. FD may be the tip of the iceberg, and accompanying complications may remain undetected in a significant proportion of patients. Until now, there was no consensus on whether a complete abdominal exploration is mandatory during post-RC dehiscence repair. Our findings suggest a need for heightened vigilance due to possible subclinical complications associated with FD. Therefore, exploratory laparotomy should be performed while carefully examining all anastomotic sites.