In the absence of alarm symptoms, most surgeons prefer conservative treatment (Ten Broek, 2018). Conservative treatment is generally associated with a lower risk of complications and shorter length of hospital stay (Krielen, 2023). In the long term, however, conservative treatment is associated with more recurrences and some of the initially conservatively treated group also require surgery later (Behman, 2019). Some surgeons therefore prefer a more aggressive approach with accessible direct surgery, even in patients without alarm symptoms.

Summary of Findings table: Surgical treatment versus conservative treatment for ASBO

Population: Patients with ABSO

Intervention: Surgical treatment

Comparator: Conservative treatment

^1.Risk of Bias: serious.

Imprecision: serious.

Description of studies

A total of four studies were included in the analysis of the literature. Important study characteristics and results are summarized in table 2. The assessment of the risk of bias is summarized in the risk of bias tables (under the tab ‘Evidence tabellen’).

Mazzetti (2018) conducted a single-center retrospective study to evaluate the advantages of early laparoscopic adhesiolysis. Patients admitted with a diagnosis of ASBO were included from January 2010 to April 2017 and underwent medical treatment, early surgery, emergency surgery, or delayed surgery after failure of medical treatment. In accordance with the intention to treat principle, patients undergoing delayed surgery were combined with the medical treatment group for the current analyses. Patients undergoing emergency surgery were excluded from the current analyses (patients who presented signs of gravity at Ct scan or signs of peritoneal irritation).

Assenza (2016) conducted a single-center retrospective study (2005 to 2014) to determine the clinical, hematochemical and radiological parameters that can indicate whether patients with aSBO should be surgically treated within 24 hours after admission or if a conservative therapy is more appropriate.

Krielen (2016) conducted a single-center retrospective study aimed at an accurate cost estimate of the in-hospital costs for treatment of ASBO. A sample of consecutive patients admitted with ASBO to the Radboudumc between November 2013 and November 2015 were included. ASBO was defined as an episode with operative confirmation of adhesions, or in the non-operative group as an episode of postoperative SBO in which other potential causes of bowel obstruction were excluded by appropriate means.

Schraufnagel (2013) conducted a nationwide retrospective study to probe the relationship between operative delay and adverse outcomes or death in ASBO using the Nationwide Inpatient Sample (a database of inpatient hospitalizations created as part of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality an agency of the US Department of Health and Human Services). Records with a primary diagnosis DRG International Classification of DiseasesV9th Rev. (ICD-9) code value of 560.81; intestinal or peritoneal adhesions with obstruction or 560.9; and unspecified intestinal obstruction were included. Patients included patients requiring surgery and patients managed nonoperatively successfully. Patients who were operated could be divided into early and delayed operation (>4 days) and were used for the current analyses.

Table 3. Characteristics of included studies

*For further details, see risk of bias table in the appendix

Results

Mortality (critical)

One study reported on this outcome. Schraufnagel (2013) reported that 138 of the 4826 patients who received surgical treatment (2.86%) and 138 of the 22220 patients who underwent conservative treatment (0.62%) died (RD 0.02, 95% CI 0.02 to 0.03).

Complications (critical)

Morbidity

One study reported on this outcome. Mazzetti (2018) reported that none of both groups had morbidity after treatment (RD 0, 95% CI -0.07 to 0.07).

Complications

Two studies reported on this outcome, but did not further define the type of ‘complications’. Mazzetti (2018) reported that 3 of the 20 patients who received surgical treatment (15%) and 14 of the 97 patients who underwent conservative treatment (14.4%) had major or minor complications (RD 0.01, 95% CI -0.17 to 0.18). Krielen (2016) reported that 10 of the 19 patients who received surgical treatment (52.6%) and 2 of the 20 patients who underwent conservative treatment (10%) had complications (RD 0.43, 95% CI 0.17 to 0.69).

Delayed surgery

One study reported on this outcome. Mazzetti (2018) reported that 22 of the 97 patients starting with medical treatment (23%) underwent delayed surgery.

Length of hospital stay

Three studies reported on this outcome (Mazetti, 2018; Krielen, 2016; Schraufnagel, 2013). No meta-analysis could be performed due to a lack of complete outcome data by Schraufnagel. The difference in length of hospital stay were clinically relevant in favor of conservative treatment in Krielen (2016) and Schraufnagel (2013).

Table 4. Length of hospital stay, mean (SD) in days

SD= standard deviation, CI= confidence interval

Recurrences

One study reported on this outcome. Mazzetti (2018) reported that 1 of the 20 patients who received surgical treatment (5%) and 21of the 97 patients who underwent conservative treatment (21.6%) exhibited recurrences (RD -0.17, 95% CI -0.29 to -0.04).

ICU admissions

One study reported on this outcome. Krielen (2016) reported that 1 of the 19 patients who received surgical treatment (5.3%) and none of the 20 patients who underwent conservative treatment (0%) were admitted to the ICU (RD 0.05, 95% CI -0.08 to 0.19).

The guideline panel considered mortality, morbidity, septic complication, admission to intensive care, organ injury or failure, readmission as critical outcome measures for decision making; and the incidence and duration of nausea and vomiting, patient-reported perception of ileus and quality of life as important outcome measures for decision making. The minimal clinically (patient) important differences are presented in the last column.

Nausea and vomiting (important)

Vomit

One study reported on this outcome. Assenza (2016) reported that 150 of the 225 patients who received surgical treatment (66%) and 50 of the 88 patients who underwent conservative treatment (56%) vomited (RD 0.10, 95% CI -0.02 to 0.22).

Stoppage of flatus and/or defecation

One study reported on this outcome. Assenza (2016) reported that 87 of the 225 patients who received surgical treatment (38%) and 35 of the 88 patients who underwent conservative treatment (38%) had stoppage of flatus and/or defecation (RD -0.01, 95% CI -0.13 to 0.11).

Patient reported perception of ASBO (important)

Not reported

Quality of life (important)

Not reported

A systematic review of the literature was performed to answer the following question(s):

What are the favorable and unfavorable effects of early/direct surgery compared to conservative trial treatment in patients with adhesional small bowel obstruction (ASBO)?

Table 1. PICO

Relevant outcome measures

The guideline panel defined the outcome measures based on the core outcome set for postoperative ileus (Tripartite Gastrointestinal Recovery Post-operative IIeus Group 2022)(Table 2). The guideline panel considered mortality, morbidity, septic complication, admission to intensive care, organ injury or failure, readmission as critical outcome measures for decision making; and the incidence and duration of nausea and vomiting, patient-reported perception of ileus and quality of life as important outcome measures for decision making. The minimal clinically (patient) important differences are presented in the last column.

Table 2. Defined outcome measures

Search and select (Methods)

The databases Embase (via Embase.com) and Medline (via OVID) were searched with relevant search terms until 26-05-2024 and 30-05-2024, respectively. The detailed search strategy is listed under the tab ‘Literature search strategy’. The systematic literature search resulted in 1180 hits. Studies were selected based on the following criteria:

• SR, RCT, observational studies;
• Patients included patients diagnosed with ASBO;
• One of the outcomes was reported.

Twenty two studies were initially selected based on title and abstract screening. After reading the full text, 18 studies were excluded (see the exclusion table under the tab ‘Evidence tabellen’), and four studies were included.