Risk Factors for Postoperative Ileus after Scoliosis Surgery

Utility of Abdominal Radiographs After Posterior Spinal Fusion for Neuromuscular Scoliosis

Background/Objectives: Postoperative ileus, the temporary cessation of gastrointestinal motility leading to accumulation of fluid and gas in the bowel, is a common complication following posterior spine fusion (PSF) in patients with neuromuscular scoliosis (NMS). Abdominal radiographs (KUBs) are often ordered to differentiate between ileus and mechanical obstruction but expose patients to radiation, add cost, and may lead to unnecessary work up. The aim of this study was to determine how often KUBs led to a change in treatment after PSF in patients with NMS. Methods: A retrospective review was conducted of NMS patients with ≥2-year follow-up treated with PSF between January 2014 and December 2019 at a tertiary pediatric hospital. Results: Of the 133 patients (age 13.7, SD 2.6 years; preoperative curve magnitude 82.8, SD 23.0 degrees; follow-up 44.7, SD 15.4 months), 22.6% (30/133) underwent KUB imaging due to abdominal pain, distension, or delayed return of bowel function. In total, 93.3% (28/30) of the KUB imaging was consistent with ileus. One KUB study resulted in a gastroenterology consultation and bowel cleanout, and one raised concerns regarding possible pneumatosis of the colon, prompting a pediatric surgery consultation and exploratory laparotomy which was unremarkable. Conclusions: KUBs were performed in nearly 25% of NMS patients during the acute postoperative period, but rarely provided useful diagnostic information leading to changes in management. In the presence of postoperative abdominal distension, feeding intolerance, and delayed return of bowel function, we advocate for continuing conservative measures until bowel function returns, reserving abdominal radiographs for patients with a worsening exam despite bowel rest or additional causes for concern.

Risk Factors for Postoperative Ileus Following Spine Surgery: A Systematic Review With Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

Postoperative ileus (POI) can negatively impact patient recovery and surgical outcomes after spine surgery. Emerging studies have focused on the risk factors for POI after spine surgery. This study aimed to review the available literature on risk factors associated with POI following elective spine surgery.

METHODS

Electronic databases were searched to identify relevant studies. Meta-analysis was performed using random-effect model. Risk factors for POI were summarized using pooled odds ratio (OR) with 95% confidence intervals (CI).

RESULTS

Twelve studies were included in the present review. Meta-analysis demonstrated males exhibited a higher risk of POI than females odds ratio (OR, 1.76; 95% CI, 1.54-2.01). Patients with anemia had a higher risk of POI than those without anemia (OR, 1.48; 95% CI, 1.04-2.11). Patients with liver disease (OR, 3.3; 95% CI, 1.2-9.08) had a higher risk of POI. The presence of perioperative fluid and electrolyte imbalances was a predictor of POI (OR, 3.24; 95% CI, 2.62-4.02). Spine surgery involving more than 3 levels had a higher risk of POI compared to that with 1-2 levels (OR, 1.82; 95% CI, 1.03-3.23).

CONCLUSIONS

Male sex and the presence of anemia and liver disease were significant patient factors associated with POI. Perioperative fluid and electrolyte imbalance and multilevel spine surgery significantly increased the risk of POI. In addition, through this comprehensive review, we identified several perioperative risk factors associated with the development of POI after spine surgery.

Risk Factors for Postoperative Ileus in Patients Undergoing Spine Surgery

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

Postoperative ileus (POI) is a common complication following elective spinal surgeries. The aim of this study was to determine the incidence of POI and identify demographic and surgical risk factors for developing POI after elective instrumented fusion of the thoracolumbar spine.

METHODS

The University of Utah Institutional Review Board (IRB) approved this retrospective study. The study does not require informed consent given the data reviewed was deidentified and collected in accordance with the institution's standard of care. A designated IRB committee determined that study is exempt under exemption category 7. IRB approval number 00069703. Patients undergoing instrumented thoracolumbar fusion for one or more levels were retrospectively identified from an internal spine surgery database. Cases performed for trauma, infection, or tumors were excluded. Demographics, medical comorbidities, surgical variables, and opioid medication administration (morphine milligram equivalents, MME) were abstracted from the electronic medical record. Univariate analysis was used to identify variables associated with POI. These variables were then tested for independent association with POI using multivariate logistic regression.

RESULTS

418 patients were included in the current study. The incidence of POI was 9.3% in this cohort. There was no significant relationship between development of POI and patient age, gender, BMI, diabetes mellitus, thyroid dysfunction, lung disease, CKD, GERD, smoking status, alcohol abuse, anemia, or prior abdominal surgery. Univariate analysis demonstrated significant association between POI and fusion ≥7 levels compared to fusions of fewer levels (P = .001), as well as intraoperative sufentanil compared to other opioids (35.9% vs 20.1%, P = .02). POI was not significantly associated with total intraoperative MME, approach, use of interbody cage, or osteotomy. Multivariate logistic regression confirmed total 24-hour postoperative MME as an independent risk factor for POI (OR 1.004, P = .04), however, intraoperative sufentanil administration was not an independent risk factor for POI when controlling for other variables.

CONCLUSIONS

This retrospective cohort study demonstrates that greater postoperative MME is an independent risk factor for POI after thoracolumbar spine fusion when accounting for demographic, medical, and surgical variables with multiple logistic regression. Prospective studies are warranted to evaluate clinical measures to decrease the risk of POI among patients undergoing instrumented thoracolumbar spinal fusions.

General anesthesia combined with bilateral 2-level erector spinae plane block may accelerate postoperative gastrointestinal function recovery and rehabilitation process in patients undergoing posterior lumbar surgery: A randomized controlled trial

BACKGROUND

This randomized controlled trial explored whether bilateral 2-level erector spinae plane block could accelerate postoperative gastrointestinal function and rehabilitation in patients undergoing posterior lumbar surgery.

METHODS

A total of 80 adult patients undergoing posterior lumbar surgery between March 2021 and August 2021 were randomized to either ultrasound-guided bilateral 2-level erector spinae plane block (group E) or not (group C). General anesthesia was routinely performed. The primary outcome was the time of the first flatus after surgery. We also recorded the first food and liquid intake, first off-bed activity, days of hospital stay, and postoperative complications. Postoperative visual analog scale score and opioid consumption were also recorded. A venous blood sample was taken to measure the serum concentration of lipopolysaccharides, c-reactive protein, tumor necrosis factor-alpha, interleukin-6, and blood glucose before induction of anesthesia, immediately after, and 24 and 48 hours after surgery.

RESULTS

Seventy-seven patients, 39 in group C and 38 in group E, finished the trial. Patients in group E had a significantly shorter time to first flatus (16.2 ± 3.2 vs 19.7 ± 3.0 hours, P < .05), earlier liquid intake (1.7 ± 0.2 vs 1.9 ± 0.3 hours, P < .05), earlier food intake (1.9 ± 0.2 vs 2.1 ± 0.3 hours, P < .05), and first off-bed activity (27.9 ± 3.2 vs 31.4 ± 3.3 h, P < .05). Patients in group E had shorter postoperative hospital stay (4.6 [4.2-5.5] d vs 5.4 [4.5-6.3], P < .05). We found that patients in group E had less pain and total sufentanil consumption (129 [120-133] vs 138 [132-147] μg, P < .05) within 24 hours after surgery. At 24 hours after surgery, the serum concentrations of lipopolysaccharides, tumor necrosis factor-alpha, interleukin-6, and C-reactive protein in group E were significantly decreased compared to group C (P < .05).

CONCLUSION

Bilateral 2-level erector spinae plane block can accelerate gastrointestinal function recovery and shorten the length of hospital stay in patients undergoing open posterior lumbar surgery. The potential mechanism may attribute to the opioids-sparing effects and anti-stress-related anti-inflammatory effects of bilateral 2-level erector spinae plane block.

Anesthesia and Perioperative Management for Surgical Correction of Neuromuscular Scoliosis in Children: A Narrative Review

Scoliosis is the most frequent spinal deformity in children. It is defined as a spine deviation of more than 10° in the frontal plane. Neuromuscular scoliosis is associated with a heterogeneous spectrum of muscular or neurological symptoms. Anesthesia and surgery for neuromuscular scoliosis have a higher risk of perioperative complications than for idiopathic scoliosis. However, patients and their relatives report improved quality of life after the surgery. The challenges for the anesthetic team result from the specifics of the anesthesia, the scoliosis surgery itself, or factors associated with neuromuscular disorders. This article includes details of preanesthetic evaluation, intraoperative management, and postoperative care in the intensive care unit from an anesthetic view. In summary, adequate care for patients who have neuromuscular scoliosis requires interdisciplinary cooperation. This comprehensive review covers information about the perioperative management of neuromuscular scoliosis for all healthcare providers who take care of these patients during the perioperative period, with an emphasis on anesthesia management.

Postoperative ileus risk after posterior thoracolumbar fusion performed with total intravenous anesthesia versus inhaled anesthesia

OBJECTIVE

There has been an increase in the use of total intravenous anesthesia (TIVA) for intraoperative neuromonitoring during thoracolumbar posterior spinal fusion (PSF). Although prior studies have identified risk factors for postoperative ileus (PI) after PSF, to the authors' knowledge, PI rates in patients receiving inhaled anesthetic versus TIVA have not been evaluated. In this study the authors analyzed whether TIVA is associated with greater risk of PI in PSF patients.

METHODS

In this retrospective single-institution cohort study, all patients undergoing PSF at the authors' tertiary academic institution from May 2014 to December 2020 were included. Patients undergoing anterior/lateral approaches or who had concurrent abdominal procedures unrelated to ileus in the same admission were excluded. PI was defined using radiographic and/or clinical diagnoses (postoperative radiographs, abdominal CT, and/or ICD-9 or -10 codes) and was confirmed via chart review. The use of TIVA or inhaled anesthetic was captured from the anesthesia record; patients were excluded if they were missing anesthesia technique data. Postoperative occurrence of PI was compared between patients who had TIVA or inhaled anesthetics while controlling for collected demographic, clinical, and surgical variables.

RESULTS

Of the 2819 patients meeting inclusion criteria, 283 (10.0%) had PI (mean ± SD age 59.3 ± 15.8 years; 155 [54.8%] male). The mean patient length of stay was 7.7 ± 5.0 days, which was significantly longer than that of patients without PI (4.9 ± 3.9 days, p < 0.001). Patients with PI had more levels fused (46% of PI patients with ≥ 5 levels fused vs 25% of non-PI patients, p < 0.001) and longer operations (6.0 ± 2.2 vs 5.4 ± 1.9 hours, p < 0.001). TIVA patients were more likely than inhalation-only patients to experience PI, but this finding did not reach significance on univariate analysis (11.0% PI rate vs 8.9%, p = 0.06). After propensity matching 125 non-PI patients and 50 PI patients by age, sex, operative time, and number of levels fused, there was a significant difference in intraoperative opiate dosing between TIVA and inhalational patients (275.7 ± 187.5 intravenous morphine milligram equivalents vs 120.9 ± 155.5, p < 0.001). On multivariate analysis of PI outcome, TIVA was an independently significant predictor (OR 1.45, p = 0.02), as was anesthesia time (OR per hour increase: 1.09, p = 0.03) and ≥ 8 levels fused (OR 1.86, p = 0.01).

CONCLUSIONS

In a large cohort of PSF patients, TIVA was associated with a higher rate of PI compared with inhaled anesthetic. This effect is likely due to higher intraoperative opiate use in these patients.

Incidence and Risk Factors for Postoperative Ileus after Posterior Surgery in Adolescent Idiopathic Scoliosis

OBJECTIVE

Postoperative ileus (POI) is a relatively common complication after spinal fusion surgery, which can lead to delayed recovery, prolonged length of stay and increased medical costs. However, little is known about the incidence and risk factors of POI after corrective surgery for patients with adolescent idiopathic scoliosis (AIS). This study was performed to report the incidence of POI and identify the independent risk factors for POI after postoperative corrective surgery.

METHODS

In this retrospective cohort study, A total of 318 patients with AIS who underwent corrective surgery from April 2015 to February 2021 were enrolled and divided into two groups: those with POI and those without POI. The Student's t test, Mann-Whitney U test, and Pearson's chi-square test were used to compare the two groups regarding patient demographics and preoperative characteristics (age, sex and the major curve type), intraoperative and postoperative parameters (lowest instrumented vertebra [LIV], number of screws, and length of stay), radiographic parameters (T5-12 thoracic kyphosis [TK], T10-L2 thoracolumbar kyphosis and height [TLK and T10-L2 height], L1-S1 lumbar lordosis [LL], and L1-5 height). Then, a multivariate logistic regression analysis was used to identify independent risk factors for POI, and a receiver operating characteristic (ROC) curve was performed to assess the predictive values of these risk factors.

RESULTS

Forty-two (13.2%) of 318 patients who developed POI following corrective surgery were identified. The group with POI had a significantly longer length of stay, more lumbar screws, higher proportions of a major lumbar curve and lumbar anterior screw breech, and a lower LIV. Among radiographic parameters, the mean lumbar Cobb angle at baseline, the changes in the lumbar Cobb angle, and T10-L2 and L1-5 height from before to after surgery were significantly larger in the group with POI than in the group without POI. Multivariate logistic regression analysis showed that large changes in T10-L2 (odds ratio [OR] =2.846, P = 0.007) and L1-5 height (OR = 31.294, p = 0.000) and lumbar anterior screw breech (OR = 5.561, P = 0.006) were independent risk factors for POI. The cutoff values for the changes in T10-L2 and L1-5 height were 1.885 cm and 1.195 cm, respectively.

CONCLUSION

In this study, we identified that large changes in T10-L2 and L1-5 height and lumbar anterior screw breech were independent risk factors for POI after corrective surgery. Improving the accuracy of pedicle screw placement might reduce the incidence of POI, and greater attention should be given to patients who are likely to have large changes in T10-L2 and L1-5 height after corrective surgery.

Alvimopan for the reduction of postoperative ileus after long posterior spinal fusion: placebo-controlled double-blind randomized trial

OBJECTIVE

The aim of this study was to evaluate the efficacy of alvimopan administration after posterior spinal fusion (PSF) in adult spine surgery patients who are taking opioid agents.

METHODS

In this placebo-controlled, double-blind randomized trial, PSF patients were randomized in blocks to placebo or study drug. Primary and secondary outcome measures were return to normal bowel function, including time to passage of flatus and stool, time to tolerance of oral nutrition, and time to hospital discharge. Patients were included regardless of chronic opioid consumption status.

RESULTS

Thirty-one patients provided consent for participation, and 26 patients (13 per group) completed the study. There were no differences between groups with respect to time to flatus, time to bowel movement, time to oral nutrition tolerance, and time to discharge. Calculated effect sizes favored placebo for all interventions.

CONCLUSIONS

Alvimopan did not hasten return to bowel function for any primary or secondary outcome measures when compared with placebo for patients undergoing PSF. There were no adverse events related to alvimopan, including for patients with chronic opioid consumption. While underpowered to determine a statistical difference, it is unlikely that a clinically relevant effect exists.

What Are Risk Factors for an Ileus After Posterior Spine Surgery?-A Case Control Study

STUDY DESIGN

Case-Control Study.

OBJECTIVE

The purpose of this retrospective study is to evaluate risk factors for developing a postoperative ileus after posterior spine surgery.

METHODS

Patient charts, including radiographs were evaluated retrospectively. Diagnosis of an ileus was confirmed radiographically by a CT scan in all cases. The control group was retrieved by selecting a random sample of patients undergoing posterior spine surgery who did not develop bowel dysfunction postoperatively.

RESULTS

A total of 40 patients had a postoperative ileus. The control group consisted of 80 patients. Both groups did not differ significantly in age, gender, BMI, tobacco use, comorbidities or status of previous abdominal surgery. Significant differences between the 2 groups was the length of stay (5.9 vs. 11.2; p = 0.001), surgery in the lumbar spine (47.5% vs. 87.5%; p < 0.001) and major spine surgery involving > 3 levels (35.0% vs. 57.5%; p = 0.019). Patients who suffered from an ileus were more likely to be treated in ICU (23.8% vs. 37.5%; p = 0.115), being re-admitted (0.0% vs 5.0%; p = 0.044) and having a delayed discharge (32.5% vs. 57.5%; p = 0.009). Multivariable analysis demonstrated that lumbar spine surgery compared to thoracic and/or cervical spine surgery (p = 0.00, OR 8.7 CI 2.9-25.4) and major spine surgery involving > 3 levels (p = 0.012; OR 3.0, CI 1.3-7.2) are associated with developing an ileus postoperatively.

CONCLUSION

Surgeries of the lumbar spine as well as those involving > 3 levels are associated with developing a postoperative ileus. Further studies are needed to expand on possible risk factors and to better understand the mechanism underlying postoperative ileus in spine surgery patients.

Clinical Importance, Incidence and Risk Factors for the Development of Postoperative Ileus Following Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective observational study of a cohort of consecutive patients.

OBJECTIVES

Postoperative ileus (POI) is associated with a variety of adverse effects. Although the incidence of and risk factors for POI following spinal surgery have been reported, the frequency and pathology of POI after spinal corrective surgery for adult spinal deformity (ASD) are still largely unknown. The study objectives were to: (1) clarify the prevalence and clinical significance of POI, (2) elucidate the risk factors for POI, (3) determine radiographically which preoperative and/or postoperative spinal parameters predominantly influence the risk of POI after spinal corrective surgery for ASD.

METHODS

We included data from 144 consecutive patients who underwent spinal corrective surgery. Perioperative medical complications and clinical information were extracted from patient electronic medical records. Preoperative radiographic parameters and changes in radiographic parameters after surgery were compared between patients with and without POI. Multivariate logistic regression analyses were performed to clarify potential risk factors for POI.

RESULTS

POI developed in 25/144 (17.4%) patients and was the most common complication in the present study. The frequencies of smoking, gastroesophageal reflux disease, and lateral lumbar interbody fusion (LLIF), as well as the duration of surgery were significantly greater in the group with POI versus the group without POI. Among radiographic parameters, only the change in thoracolumbar kyphosis (TLK) from before to after surgery was significantly larger in the group with POI. Multivariate logistic regression analysis showed that male sex, LLIF and large changes in TLK from before to after surgery were significantly associated with the development of POI.

CONCLUSIONS

These results suggested that LLIF and large corrections in TLK were independent risk factors for POI after ASD surgery. When patients with ASD have large TLK preoperatively, and it is determined that a large correction is needed, physicians must be aware of the potential for occurrence of POI.

Risk factors for gastrointestinal complications after spinal fusion in children with cerebral palsy

DESIGN

Prospective cerebral palsy (CP) registry review.

OBJECTIVES

(1) Evaluate the incidence/risk factors of gastrointestinal (GI) complications in CP patients after spinal fusion (SF); and (2) investigate the validity of the modified Clavien-Dindo-Sink classification.

BACKGROUND

Perioperative GI complications result in increased length of stay (LOS) and patient morbidity/mortality. However, none have analyzed the outcomes of GI complications using an objective classification system.

METHODS

A prospective/multicenter CP database identified 425 children (mean, 14.4 ± 2.9 years; range, 7.9-21 years) who underwent SF. GI complications were categorized using the modified Clavien-Dindo-Sink classification. Grades I-II were minor complications and grades III-V major. Patients with and without GI complications were compared.

RESULTS

87 GI complications developed in 69 patients (16.2%): 39 minor (57%) and 30 major (43%). Most common were pancreatitis (n = 45) and ileus (n = 22). Patients with preoperative G-tubes had 2.2 × odds of developing a GI complication compared to oral-only feeders (OR 2.2; 95% CI 0.98-4.78; p = 0.006). Similarly, combined G-tube/oral feeders had 6.7 × odds compared to oral-only (OR 6.7; 95% CI 3.10-14.66; p < 0.001). The likelihood of developing a GI complication was 3.4 × with normalized estimated blood loss (nEBL) ≥ 3 ml/kg/level fused (OR 3.41; 95% CI 1.95-5.95; p < 0.001). Patients with GI complications had more fundoplications (29% vs. 17%; p = 0.03) and longer G-tube fasting periods (3 days vs. 2 days; p < 0.001), oral fasting periods (5 days vs. 2 days; p < 0.001), ICU admissions (6 days vs. 3 days; p = 0.002), and LOS (15 days vs. 8 days; p < 0.001). LOS correlated with the Clavien-Dino-Sink classification.

CONCLUSION

Gastrointestinal complications such as pancreatitis and ileus are not uncommon after SF in children with CP. This is the first study to investigate the validity of the modified Clavien-Dindo-Sink classification in GI complications after SF. Our results suggest a correlation between complication severity grade and LOS. The complexity of perioperative enteral nutritional supplementation requires prospective studies dedicated to enteral feeding protocols.

LEVEL OF EVIDENCE

Therapeutic-level III.