This study was designed to assess the effect of elective surgery with adhesiolysis in patients with chronic adhesion-related pain on the long-term incidence of ASBO, predictive factors of readmission of ASBO and patient-reported abdominal symptoms. Adhesiolysis with an anti-adhesive barrier reduced the occurrence of ASBO by a factor four to 6.5 percent in the whole cohort and by a factor three to 15 percent in patients with one or more previous episodes of ASBO. In comparison, the incidence of ASBO is 2% in patients after any abdominal surgery and 10% in patients after colorectal surgery (4, 21). We found no other risk factors than adhesiolysis and previous ASBO. Elective adhesiolysis reduced most patient-reported long-term chronic abdominal symptoms and the use of healthcare services. Altogether, elective adhesiolysis with barrier use for chronic abdominal pain has a broader impact on a patient’s life than just long-term pain relief.
The topic of elective adhesiolysis has been surrounded by some controversies, regarding its effectiveness, indications, surgical technique, and safety. The main body of literature on elective adhesiolysis addresses chronic adhesion-related pain, with several additional case series reporting on elective adhesiolysis for recurrent ASBO (12, 13, 15). Most studies reporting on adhesiolysis for chronic pain reported a good initial, short-term, response in 70–80% of patients (22). In a trial randomizing between diagnostic laparoscopy and adhesiolysis, the recurrence of symptoms at one year was high in both groups (23). However, no barriers were used in this trial. In a recent study from our group, 80% of patients reported improvement in pain after 1.5 years following elective adhesiolysis with a barrier (5). Also in a trial by Cheong et al. adhesiolysis with a barrier resulted in significant improvement of pain at 6 months, as compared to diagnostic laparoscopy (24). Thus, recent studies suggest that adhesiolysis with barriers can be effective in selected patients reducing chronic pain and improving quality of life.
The lowered occurrence rate of ASBO following elective surgery with adhesiolysis and the application of a barrier add to the potential benefits of this procedure. ASBO is an acute surgical condition that is usually considered resolved after treatment. However, ASBO inherits a high risk of recurrence and can also impact the long-term quality of life (11, 12, 25). Recurrence risk following conservative treatment is 21%-25% and following operative management 13%-19% in the first ten years after the first episode of ASBO (10, 11). With every new episode of ASBO the risk of recurrent episodes increases and the interval between episodes decreases, resulting in a considerable number of patients developing rapidly recurring episodes of ASBO (26). Some patients with recurrent ASBO end up on liquid or low-residue diets to prevent new episodes of readmission (27). Question remains whether or not elective adhesiolysis should be considered for patients presenting with recurrent ASBO as the main symptom. Two small case series reported some favorable results performing elective adhesiolysis for this indication (12, 14). In these series, up to one in eight patients developed a recurrent episode of ASBO during four to five years of follow-up following elective adhesiolysis. Patients had a median of two to three previous episodes of ASBO. These studies lacked a control group, nevertheless, these results seem to compare favorably to the 30–60% 10-year recurrence rates reported in the natural course of patients with multiple episodes of ASBO in history (28). In our study, the risk of recurrent ASBO in the subgroup of patients with previous ASBO was considerably lower after adhesiolysis when compared to the non-operative group; the latter was at a comparable risk for developing recurrent episodes as expected from reports on natural course. In both our cohort, and previous series reporting on elective adhesiolysis most patients had less than four episodes prior to surgery. Epidemiological data shows that with more episodes the risk of recurrence increases with a shortening interval between episodes. In patients with a high frequency of recurrence, new episodes might therefore be more difficult to prevent (28, 29).
A benefit of performing adhesiolysis as elective surgery and not as an emergency procedure to reduce the risk of recurrent ASBO is the lower risk of iatrogenic injuries and mortality. In the NELA report, 30-day mortality associated with emergency adhesiolysis was 5%, which increased to 11.8% in high-risk patients with factors such as frailty, elderly, or comorbidities (30, 31). In the emergency setting, patients are admitted in a deteriorated condition. The distended bowel in the emergency setting increases the risk of conversion and injuries during surgical handling (32, 33). In contrast, elective adhesiolysis can be considered a safer procedure. A few bowel injuries were found which healed uneventfully mostly after simple primary closure and there were no postoperative deaths.
Although we included a relatively large number of patients undergoing elective adhesiolysis, a limitation of this study is the relatively small size of different subgroups. Results on treatment and outcome of new episodes of ASBO should therefore be interpreted with caution. Readmission for ASBO is a commonly used outcome for follow-up studies on ASBO and is easy to establish objectively. Nevertheless, in patients with frequent episodes, mild cases of obstructive symptoms might not always result in admission. Another potential limitation is selection bias, as patients were allocated to treatment shared-decision making and not by randomization. Potentially, patients with more extensive adhesions on CineMRI imaging who are at an increased risk of iatrogenic injuries during adhesiolysis might have been more prone to be allocated to the non-operative group, resulting in more favorable results for the operative group. However, from our experience and review of patient files, extensive adhesions were only seldom the main reason to choose non-operative treatment. In most cases, other patient factors or patient preferences were the decisive factors for treatment decisions. The extent of adhesions also seemed evenly distributed among groups at baseline comparison.
Given the high risk of ASBO in patients with chronic adhesion-related pain, reducing the risk of ASBO can be an additional benefit when considering operative treatment. Results also seem promising for patients presenting with recurrent small bowel obstruction, with or without chronic pain. Data for patients with a high frequency of recurrence (i.e. 4 episodes or more) of ASBO, however, remains limited. The potential benefits of reducing the risk of recurrence should be weighed against the risks of an operation. Although adhesiolysis is associated with some considerable risk, and iatrogenic bowel injury, in particular, there is also growing evidence for the important impact of preventing recurrences of ASBO. In a recent analysis Behman. et al. demonstrated an improved long-term survival of ASBO after emergency operative treatment as compared to conservative treatment, mediated by a lower risk of recurrence. (10) The lower operative risks of elective adhesiolysis might contribute to an even greater benefit.