Development of a postoperative ileus risk assessment scale: identification of intraoperative opioid exposure as a significant predictor after spinal surgery

The Evolution of Risk Assessment in Spine Surgery: A Narrative Review

BACKGROUND

Risk assessment is critically important in elective and high-risk interventions, particularly spine surgery. This narrative review describes the evolution of risk assessment from the earliest instruments focused on general surgical risk stratification, to more accurate and spine-specific risk calculators that quantified risk, to the current era of big data.

METHODS

The PubMed and SCOPUS databases were queried on October 11, 2023 using search terms to identify risk assessment tools (RATs) in spine surgery. A total of 108 manuscripts were included after screening with full-text review using the following inclusion criteria: 1) study population of adult spine surgical patients, 2) studies describing validation and subsequent performance of preoperative RATs, and 3) studies published in English.

RESULTS

Early RATs provided stratified patients into broad categories and allowed for improved communication between physicians. Subsequent risk calculators attempted to quantify risk by estimating general outcomes such as mortality, but then evolved to estimate spine-specific surgical complications. The integration of novel concepts such as invasiveness, frailty, genetic biomarkers, and sarcopenia led to the development of more sophisticated predictive models that estimate the risk of spine-specific complications and long-term outcomes.

CONCLUSIONS

RATs have undergone a transformative shift from generalized risk stratification to quantitative predictive models. The next generation of tools will likely involve integration of radiographic and genetic biomarkers, machine learning, and artificial intelligence to improve the accuracy of these models and better inform patients, surgeons, and payers.

Regional Anesthesia Techniques in Modern Neuroanesthesia Practice: A Narrative Review of the Clinical Evidence

Neurosurgical procedures are often associated with significant postoperative pain that is both underrecognized and undertreated. Given the potentially undesirable side effects associated with general anesthesia and with various pharmacological analgesic regimens, regional anesthetic techniques have gained in popularity as alternatives for providing both anesthesia and analgesia for the neurosurgical patient. The aim of this narrative review is to present an overview of the regional techniques that have been incorporated and continue to be incorporated into modern neuroanesthesia practice, presenting in a comprehensive way the evidence, where available, in support of such practice for the neurosurgical patient.

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.

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.

Randomized clinical trial comparing outcomes after fentanyl or ketamine-dexmedetomidine analgesia in thoracolumbar spinal surgery in dogs

Background

Opioids are widely used for perioperative pain control in dogs undergoing spinal surgery, but alternatives may be required because data suggest that opioids exacerbate inflammation in the injured spinal cord and veterinary access to opioids may become more restricted in the future.

Objectives

To compare recovery of ambulation and other functions between spinal cord‐injured dogs receiving peri‐operative fentanyl and those receiving a ketamine‐dexmedetomidine combination.

Animals

A total of 102 client‐owned dogs undergoing decompressive surgery for thoracolumbar intervertebral disc herniation.

Methods

Randomized clinical trial. Dogs were randomized 1:1 to fentanyl or a ketamine‐dexmedetomidine combination for intra and postoperative analgesia. Primary outcome was time to recovery of ambulation; secondary outcomes were the postoperative Colorado Acute Pain Scale, the short‐form Glasgow Composite Measure Pain Scale, time to recovery of voluntary urination and time to unassisted eating.

Results

No difference was found in time to recovery of ambulation between groups (adjusted sub‐hazard ratio, 0.83; 95% confidence interval [CI], 0.55‐1.24; P = .36) or in pain scores (Colorado: χ² = 14.74; P = .32; Glasgow: χ² = 6.61; P = .76). Differences in time to recovery of eating and urination were small but favored ketamine‐dexmedetomidine (adjusted odds ratios, 3.31; 95% CI, 1.53‐7.16; P = .002 and 2.43; 95% CI, 1.00‐5.96; P = .05, respectively).

Conclusions and Clinical Importance

There was no evidence that, at the doses used, fentanyl impaired ambulatory outcome after surgery for thoracolumbar intervertebral disc herniation in dogs. Pain control appeared similar between groups. Secondary outcomes suggested minor benefits associated with ketamine‐dexmedetomidine. The ketamine‐dexmedetomidine combination appears to be a reasonable alternative to peri‐operative opioids.

Age Increases the Risk of Mortality by Four-Fold in Patients with Emergent Paralytic Ileus: Hospital Length of Stay, Sex, Frailty, and Time to Operation as Other Risk Factors

Background: In the United States, ileus accounts for USD 750 million of healthcare expenditures annually and significantly contributes to morbidity and mortality. Despite its significance, the complete picture of mortality risk factors for these patients have yet to be fully elucidated; therefore, the aim of this study is to identify mortality risk factors in patients emergently admitted with paralytic ileus. Methods: Adult and elderly patients emergently admitted with paralytic ileus between 2005−2014 were investigated using the National Inpatient Sample Database. Clinical outcomes, therapeutic management, demographics and comorbidities were collected. Associations between mortality and all other variables were established via univariable and multivariable logistic regression models. Results: A total of 81,674 patients were included, of which 45.2% were adults, 54.8% elderly patients, 45.8% male and 54.2% female. The average adult and elderly ages were 48.3 and 78.8 years, respectively. Elderly patients displayed a significantly (p < 0.01) higher mortality rate (3.0%) than adults (0.7%). The final multivariable logistic regression model showed that for every one-day delay in operation, the odds of mortality for adult and elderly patients increased by 4.1% (p = 0.002) and 3.2% (p = 0.014), respectively. Every additional year of age corresponded to 3.8% and 2.6% increases in mortality for operatively managed adult (p = 0.026) and elderly (p = 0.015) patients. Similarly, non-operatively treated adult and elderly patients displayed associations between mortality and advanced age (p = 0.001). The modified frailty index exhibited associations with mortality in operatively treated adults, conservatively managed adults and conservatively managed elderly patients (p = 0.001). Every additional day of hospitalization increased the odds of mortality in non-operative adult and elderly patients by 7.6% and 5.8%, respectively. Female sex correlated to lower mortality rates in non-operatively managed adult patients (odds ratio = 0.71, p = 0.028). Undergoing invasive diagnostic procedures in non-operatively managed elderly patients related to reduced mortality (odds ratio = 0.78, p = 0.026). Conclusions: Patients emergently admitted for paralytic ileus with increased hospital length of stay, longer time to operation, advanced age or higher modified frailty index displayed higher mortality rates. Female sex and invasive diagnostic procedures were negatively correlated with death in nonoperatively managed patients with paralytic ileus.

A machine learning algorithm for predicting prolonged postoperative opioid prescription after lumbar disc herniation surgery. An external validation study using 1,316 patients from a Taiwanese cohort

BACKGROUND CONTEXT

Preoperative prediction of prolonged postoperative opioid prescription helps identify patients for increased surveillance after surgery. The SORG machine learning model has been developed and successfully tested using 5,413 patients from the United States (US) to predict the risk of prolonged opioid prescription after surgery for lumbar disc herniation. However, external validation is an often-overlooked element in the process of incorporating prediction models in current clinical practice. This cannot be stressed enough in prediction models where medicolegal and cultural differences may play a major role.

PURPOSE

The authors aimed to investigate the generalizability of the US citizens prediction model SORG to a Taiwanese patient cohort.

STUDY DESIGN

Retrospective study at a large academic medical center in Taiwan.

PATIENT SAMPLE

Of 1,316 patients who were 20 years or older undergoing initial operative management for lumbar disc herniation between 2010 and 2018.

OUTCOME MEASURES

The primary outcome of interest was prolonged opioid prescription defined as continuing opioid prescription to at least 90 to 180 days after the first surgery for lumbar disc herniation at our institution.

METHODS

Baseline characteristics were compared between the external validation cohort and the original developmental cohorts. Discrimination (area under the receiver operating characteristic curve and the area under the precision-recall curve), calibration, overall performance (Brier score), and decision curve analysis were used to assess the performance of the SORG ML algorithm in the validation cohort. This study had no funding source or conflict of interests.

RESULTS

Overall, 1,316 patients were identified with sustained postoperative opioid prescription in 41 (3.1%) patients. The validation cohort differed from the development cohort on several variables including 93% of Taiwanese patients receiving NSAIDS preoperatively compared with 22% of US citizens patients, while 30% of Taiwanese patients received opioids versus 25% in the US. Despite these differences, the SORG prediction model retained good discrimination (area under the receiver operating characteristic curve of 0.76 and the area under the precision-recall curve of 0.33) and good overall performance (Brier score of 0.028 compared with null model Brier score of 0.030) while somewhat overestimating the chance of prolonged opioid use (calibration slope of 1.07 and calibration intercept of -0.87). Decision-curve analysis showed the SORG model was suitable for clinical use.

CONCLUSIONS

Despite differences at baseline and a very strict opioid policy, the SORG algorithm for prolonged opioid use after surgery for lumbar disc herniation has good discriminative abilities and good overall performance in a Han Chinese patient group in Taiwan. This freely available digital application can be used to identify high-risk patients and tailor prevention policies for these patients that may mitigate the long-term adverse consequence of opioid dependence: https://sorg-apps.shinyapps.io/lumbardiscopioid/.

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.

A snapshot of intraoperative conditions to predict prolonged postoperative ileus after colorectal surgery

BACKGROUND

The cause of prolonged postoperative ileus (PPOI) is multifactorial. The influence of preoperative factors on PPOI has been well documented, but little is known about the impact of intraoperative conditions. The aim of this study was to investigate the influence of intraoperative factors on PPOI in patients undergoing colorectal surgery.

METHODS

The LekCheck study database of the Colorectal Unit at the Royal Adelaide Hospital was analysed. Per patient, over 60 data points were prospectively collected between March 2018 and July 2020. Intraoperative data were collected in theatre during a one-off snapshot measure. Univariate and multivariable logistic regression analyses were performed.

RESULTS

Data of 336 patients were included. The median age was 66 years and 58.3% were male. Ninety-three patients (27.7%) developed PPOI. Univariate analysis identified the following intraoperative variables as risk-factors of PPOI: greater volumes of intraoperative IV fluid administration (464 versus 415 mL/h for those without PPOI; p = 0.04), side-to-side anastomosis orientation (53.8 versus 41.2%; p = 0.04) and increased perioperative opioid use (6.73 versus 4.11 mg/kg morphine equivalents for patients with and without PPOI, respectively; p = 0.02). Upon multivariable analysis, increased perioperative opioid use remained significant (p = 0.05), as well as the preoperative factors anticoagulation use (p = 0.04) and higher levels of serum total protein (p = 0.02).

CONCLUSION

This study suggests that intraoperative factors may also contribute to the development of PPOI, but this could not be confirmed in the multivariate analysis. Further studies including larger patient numbers will be required to determine the impact of intraoperative conditions on the development of PPOI.

A nomogram to predict prolonged postoperative ileus after intestinal resection for Crohn's disease

PURPOSE

We aim to identify the risk factors of PPOI in patients with CD and create a nomogram for prediction of PPOI for CD.

METHODS

Data on 462 patients who underwent partial intestinal resection for CD in Jin-ling Hospital between January 2019 and June 2021 were retrospectively collected. Univariate and multivariate analyses were performed to determine the risk factors for PPOI and we used the risk factors to create a nomogram. Then we used the Bootstrap-Concordance index and calibration diagrams to evaluate the performance of the Nomogram. Decision curve analysis was performed to evaluate clinical practicability of the model.

RESULTS

The incidence of PPOI was 27.7% (n of N). Course of CD ≥ 10 years, operation time ≥ 154 min, the lowest mean arterial pressure ≤ 76.2 mmHg, in-out balance per body weight ≥ 22.90 ml/kg, post-op day 1 infusion ≥ 2847 ml, post-op lowest K⁺  ≤ 3.75 mmol/L, and post-op day 1 procalcitonin ≥ 2.445 ng/ml were identified as the independent risk factors of PPOI in patients with CD. The nomogram we created by these risk factors presented with good discriminative ability (concordance index 0.723) and was moderately calibrated (bootstrapped concordance index 0.704). The results of decision curve analysis showed that the nomogram was clinically effective within probability thresholds in the 8 to 66% range.

CONCLUSION

The nomogram we developed is helpful to evaluate the risk of developing PPOI after partial intestinal resection for CD. Clinicians can take more necessary measures to prevent PPOI in CD's patients or at least minimize the incidence.

Use of a Standardized Perioperative Care Path for Adolescent Idiopathic Scoliosis Leads to Decreased Complications and Readmissions

STUDY DESIGN

Retrospective review of patients ages 10-18 who underwent posterior fusion for adolescent idiopathic scoliosis (AIS) at a single institution from 2014 to 2019.

OBJECTIVE

The aim was to evaluate a standardized Care Path to determine its effects on perioperative outcomes in patients undergoing spinal fusion for AIS.

SUMMARY OF BACKGROUND DATA

AIS is the most common pediatric spinal deformity and thousands of posterior fusions are performed annually. Surgery presents several postoperative challenges, such as pain control, delayed mobilization, and opioid-related morbidity. Optimizing perioperative care of AIS is a high priority to reduce morbidity and improving health care efficiency.

MATERIALS AND METHODS

A total of 336 patients ages 10-18 were included in this study; 117 in the pre-Care Path cohort (2014-2015) and 219 in the post-Care Path cohort (2016-2019). Data compared included intraoperative details, length of stay, timing of mobilization, inpatient complications, emergency room (ER) visits, readmissions after discharge, postoperative complications, and reoperations.

RESULTS

The post-Care Path cohort had improved mobilization on postoperative day 0 (pre 16.7%, post 53.3%, P<0.00001), reduced length of stay (pre 4.14 days, post 3.36 days, P=0.00006), fewer total inpatient complications (pre 17.1%, post 8.1%, P=0.0469), and fewer instances of postoperative ileus (pre 8.5%, post 1.9%, P=0.0102). Within 60 days of surgery, the post-Care Path cohort had fewer ER visits (pre 12.8%, post 7.2%, P=0.0413), decreased postoperative infections (pre 5.1%, post 0.48%, P=0.00547), decreased readmissions (pre 6.0%, post 0.48%, P=0.0021), and decreased reoperations (pre 5.1%, post 0.96%, P=0.0195). There was a decrease in inpatient oral morphine equivalents in the Care Path cohort (pre 118.7, post 84.7, P=0.0003).

CONCLUSIONS

Our Care Path for AIS patients demonstrated significant improvements in postoperative mobilization and decreases in length of stay, complications, infections, ER visits, readmissions, and reoperations.

Risk factors of postoperative ileus following laparoscopic radical cystectomy and developing a points-based risk assessment scale

BACKGROUND

Postoperative ileus (POI) is one of the most common complications after laparoscopic radical cystectomy (LRC). Albeit its high incidence, its risk factors are obscure, and few studies have attempted to explore them. Meanwhile, risk-assessing tools for predicting its happening are lacking.

METHODS

Clinical data of 197 patients who underwent LRC between March 2014 and October 2019 were retrospectively collected. All cases of POI were identified and double-checked. Data pertaining to the following categories were extracted as well: patients' general characteristics, preoperative laboratory tests results and preparations, intraoperative and postoperative general items, pathological results. The correlation between candidate risk factors and ileus was analyzed by multivariable binary logistic regression. Clinical and pathophysiological explanations for those results were explored. Finally, a points-based prediction model was developed and validated for predicting the happening of POI.

RESULTS

A total of 63 out of 197 patients (31.98%) suffered from POI. Multivariate logistic regression analysis showed chronic constipation, increased dosage of laxative, elevated preoperative serum creatinine level, delayed postoperative ambulation, intestine-related urine derivations were statistically significant for developing POI (P<0.05). No significant differences were found between POI and age, gender, body mass index (BMI), antibiotics, hypertension, diabetes, smoking, hard-drinking, preoperative hemoglobin level, preoperative albumin level, history of previous abdominal surgery, surgery time, intraoperative blood loss, blood transfusion, tumor size, lymph nodes yields, TNM staging and intensive care unit hospitalization. An external cohort had been used for testing the validation of the assessment scale, and the results were promising.

CONCLUSIONS

Early recognition is of great importance in protecting vulnerable patients from developing POI, knowing the above-mentioned risk factors and using the assessment scale should help to screen them better. Cases from diverse backgrounds might contribute to a more accurate and complete scale.