Underestimation of postoperative ileus as a benign complication in spine surgery: a case-control study in a major spine surgery centre in Saudi Arabia

Abstract

Background: Postoperative ileus (POI) is a common complication of spine surgery, characterized by a temporary and reversible slowdown in gastrointestinal tract movement following surgery. causes of POI are multifaceted, involving surgical stress, inflammatory agents, natural opioids in the gastrointestinal tract, hormonal alterations, and fluid and electrolyte imbalances. Despite reports on POI incidence and contributing factors, definitive research remains scarce, particularly in the Middle East. This study aims to study the prevalence, risk factors, and implication of POI following spine surgery.

Methods: This case-control study examined patient files from a tertiary specialist center from 2016 to 2022. Patients who developed POI post-spine surgery were compared with a near-matched cohort who did not, using a convenience sampling method. POI was identified based on standard definitions, excluding patients with previous spine surgeries or conditions predisposing to POI. Data collected included demographics, comorbidities, surgical indications, medications, bowel regimens, blood transfusions, perioperative blood work, intensive care unit (ICU) admissions, and mobilization documentation. Bivariable analysis identified risk factors, with categorical data analyzed using chi-square tests and continuous data using Student's t-tests. Multivariate logistic regression models adjusted for risk factors, with P<0.05 considered significant.

Results: Out of 294 spine surgery patients, 40.8% developed POI. Females constituted 75% of POI cases (P<0.001). Mean age was 40.5 years in the POI group vs. 46.1 years in the non-POI group (P=0.03). Asthma was significantly associated with POI development [15% vs. 2.9%, odds ratio (OR) =5.9, P<0.001], while diabetes was found to be protective against POI (20% vs. 33.9%, OR =0.48, P=0.009). Fentanyl use was associated with POI (97.5% vs. 85%, OR =6.89, P<0.001), as was patient-controlled analgesia (PCA) morphine (65% vs. 49.4%, OR =1.9, P=0.008). Scoliosis was strongly associated with POI development (45% vs. 19%, OR =3.49, P<0.001), particularly in the thoracic region (61.7% vs. 36.2%, OR =2.83, P<0.001). Spine fusion and increased surgery duration were also significant risk factors for POI (both P<0.001).

Conclusions: Our study demonstrates that almost half of the spine surgery cases developed POI, with asthma being the most significant risk factor. Diabetes showed a surprising protective effect. From a surgical perspective, scoliosis, particularly in the thoracic region, was strongly associated with POI. These findings emphasize the need for tailored perioperative management strategies to mitigate POI and improve patient outcomes. Further research is required to explore these associations and develop effective prevention strategies.

Keywords: Postoperative ileus (POI); complications; risk factors; spine surgery.