The Importance of Extreme Weight Percentile in Postoperative Morbidity in Children

Effect of Obesity on Surgical Outcomes and Complication Rates in Pediatric Patients: A Comprehensive Systematic Review and Meta-Analysis

Obesity is one of the primary public health problems faced by children. The increased incidence of obesity in the pediatric population poses significant challenges during and after surgical procedures. This systematic review and meta-analysis aimed to understand to what extent obesity is to surgical complications in pediatric patients. A systematic database search of PubMed, Web of Science, Scopus, and Science Direct was performed in June 2023. According to the inclusion and exclusion criteria, two evaluators independently conducted literature screening, data extraction, and quality evaluation of the retrieved literature. The Newcastle-Ottawa Scale score was used for quality evaluation, and a meta-analysis was performed using Review Manager software 5.4.1. A total of 1,170 relevant articles were initially identified, and 20 articles were finally included for data extraction and meta-analysis. The results of the meta-analysis showed that compared with normal-weight individuals, obese pediatric patients had a higher risk of developing surgical site infection (SSI) (relative risk (RR) = 1.63; 95% confidence interval (CI) = 1.33-2.00), wound dehiscence (RR = 2.01; 95% CI = 1.24-3.23), and underwent procedures that were 11.32 minutes longer (95% CI = 5.36-17.29). There were no differences in bleeding requiring transfusion, deep venous thromboembolism, postoperative abscess rate, and length of stay. Obese pediatric patients have a higher risk of SSI and dehiscence, along with a longer operative time. The established risks in obese adults undergoing surgery suggest a similar risk for obese pediatric patients. The findings of this study hold significant implications for clinical practice, suggesting the potential for additional measures to prevent surgical complications in children.

Effect of body mass index on progressive bone mineral density in patients with cleft after secondary alveolar bone grafting

BACKGROUND

Although childhood obesity matters, the association between body mass index (BMI) and bone mineral density (BMD) progression in grafted tissue after secondary alveolar bone grafting (ABG) for children with cleft alveolus is scarcely studied. Accordingly, this study explored the influence of BMI on BMD progression after ABG.

METHODS

In total, 39 patients with cleft alveolus receiving ABG at the mixed dentition stage were enrolled. Patients were classified as underweight, normal weight, or overweight or obese according to age- and sex-adjusted BMI. BMD was measured in Hounsfield units (HU) from cone-beam computed tomography scans obtained 6 months (T1) and 2 years (T2) postoperatively. Adjusted BMD (HU_{grafted tissue}/HU_pogonion, BMD_a) was used for further analysis.

RESULTS

For underweight, normal-weight, and overweight or obese patients, BMD_aT1 values were 72.87%, 91.85%, and 92.89%, respectively (p = 0.727); BMD_aT2 values were 111.49%, 112.57%, and 113.10% (p = 0.828); and density enhancement rates were 29.24%, 24.61%, and 22.14% (p = 0.936). No significant correlation was observed between BMI and BMD_aT1, BMD_aT2, or density enhancement rates (p = 0.223, 0.156, and 0.972, respectively). For patients with BMI < 17 and ≥ 17 kg/m², BMD_aT1 values were 89.80% and 92.89%, respectively (p = 0.496); BMD_aT2 values were 111.49% and 113.10% (p = 0.216); and density enhancement rates were 23.06% and 26.39% (p = 0.573).

CONCLUSION

Patients with different BMI values had similar outcomes (BMD_aT1, BMD_aT2, or density enhancement rate) after our ABG procedure in the 2-year postoperative follow-up.

Obesity is not associated with increased resource utilization or morbidity in patients undergoing appendectomy

BACKGROUND

Obesity is a growing public health concern that places patients at risk of morbidity and mortality following surgery. We sought to determine whether obesity influences our resource utilization and postoperative outcomes for patients who present with appendicitis.

METHODS

Charts were reviewed for patients age 1-18 years identified from a prospective registry who presented with a diagnosis of appendicitis from 2017 to 2020. Patients who underwent appendectomy were eligible. Charts were reviewed for demographics, imaging studies, laboratory studies, length of stay, operative times and thirty-day postoperative adverse events defined as return to the emergency room, re-admission, postoperative abscess or return to the operating room. A multivariate logistic regression analysis was performed to identify differences in resource utilization and outcome.

RESULTS

A total of 451 patients were identified. There were 126 obese patients (27.9%). Obese patients were not more likely to present with perforated appendicitis and were not more likely to undergo computed tomography scans. All patients underwent laparoscopic appendectomy. Although intraoperative times were significantly longer for Black patients and older patients, BMI did not influence length of surgery. Length of stay was significantly higher for younger patients (p = 0.019). Adverse events were seen in 38 patients (8.4%). There was no association between BMI and adverse events.

CONCLUSIONS

Within our standardized management pathway, obesity does not influence management or patient outcomes for the treatment of appendicitis. Furthermore, obese patients did not require additional resource utilization.

LEVEL OF EVIDENCE

III.

Impact of body mass index on 30-day postoperative morbidity in pediatric and adolescent patients undergoing continent urinary tract reconstruction

INTRODUCTION

Obesity has been thought to increase the risk of complications and need for additional resources with surgery, but only a limited amount of evidence is available in the pediatric population.

OBJECTIVE

The objectives were to describe the weight status of pediatric and adolescent patients undergoing a continent urinary tract reconstruction and to determine the association between obesity and 30-day postoperative morbidity.

STUDY DESIGN

A retrospective cohort study was performed for pediatric and adolescent patients aged up to 20 years who underwent a continent urinary tract reconstruction between January 2010 and November 2016. Weight status was stratified by the body mass index (BMI) for age z-scores as follows: underweight (<5th percentile), normal (5th to <85th percentiles), overweight (85th to <95th percentiles), and obese (≥95th percentile). Primary outcomes included the duration of intensive care and hospitalization as well as re-admissions and complications within 30 days.

RESULTS

A total of 182 continent reconstructions were identified during the study period. Demographic and peri-operative data are provided in the Table. Weight status was not associated with any primary outcomes on univariate or multivariate analysis. There was also no association in an analysis between the non-overweight or non-obese group (BMI for age z-score <85th) and overweight or obese group (BMI for age z-score ≥85th percentiles); a subgroup analysis between patients with and without myelomeningocele; or a subgroup analysis for wound, infectious, or high-grade (Clavien-Dindo grades III or higher) complications.

DISCUSSION

Obesity has been consistently associated with an increased risk of surgical site infections and wound complications after a wide variety of surgeries in adults. The results from the present study conflict with those of the few available studies in the pediatric population. The high-risk nature of the present cohort may have mitigated any effect of obesity on 30-day postoperative morbidity. The limitations of the present study include its retrospective design at a single center and the potential misclassification of weight status with the BMI.

CONCLUSIONS

Almost 30% of pediatric and adolescent patients undergoing a continent urinary tract reconstruction were overweight or obese. Obesity as determined by the BMI was not associated with 30-day postoperative morbidity.

The relationship between preoperative nutritional state and adverse outcome following abdominal and thoracic surgery in children: Results from the NSQIP database

INTRODUCTION

Anthropometric measurements can be used to define pediatric malnutrition. Our study aims to: (1) characterize the preoperative nutritional status of children undergoing abdominal or thoracic surgery, and (2) describe the associations between WHO-defined acute (stunting) and chronic (wasting) undernutrition (Z-scores <-2) and obesity (BMI Z-scores >+2) with 30-day postoperative outcomes.

METHODS

We queried the Pediatric NSQIP Participant Use File and extracted data on patients' age 29days to 18years who underwent abdominal or thoracic procedures. Normalized anthropometric measures were calculated, including weight-for-height for <2years, BMI for ages ≥2years, and height for age. Logistic regression models were developed to assess nutritional outlier status as an independent predictor of postoperative outcome.

RESULTS

23,714 children (88% ≥2y) were evaluated. 4272 (18%) were obese, while 2640 (11.1%) and 904 (3.8%) were stunted and wasted, respectively, after controlling for gender, ASA/procedure/wound classification, preoperative steroid use, need for preoperative nutritional support, and obese children had higher odds of SSIs (OR 1.29, 95% CI 1.1-1.5, p=0.001), while stunted children were at increased risk of any 30-day postoperative complication (OR 1.16, 95% CI 1.0-1.3, p=0.036).

CONCLUSION

Children who are stunted or obese are at increased risk of adverse outcome after abdominal or thoracic surgery.

LEVEL OF EVIDENCE

III.

Retrograde intrarenal surgery using ureteral access sheaths is a safe and effective treatment for renal stones in children weighing <20 kg

INTRODUCTION

Surgical treatment of pediatric kidney stones has changed dramatically in recent years because of the miniaturization of surgical instruments and the availability of intracorporeal lithotripters. The retrograde intrarenal surgery (RIRS) technique is nowadays considered an effective and safe procedure but studies in very young children are lacking and use of a ureteral access sheath (UAS) has also been debated.

OBJECTIVE

To assess safety and efficacy of RIRS using UAS in children weighing < 20 kg.

MATERIALS AND METHODS

Data from 13 children weighing <20 kg who underwent RIRS for renal stones were collected. A Double-J stent was positioned 14 days before surgery. Demographics, stone location, stone number and composition, stone-free status (SFS) and complications were evaluated. Descriptive statistics were applied to describe the cohort.

RESULTS

Thirteen patients, age 3.91 ± 1.8 years (mean ± SD), underwent 16 RIRS. Mean patient weight and stone burden were 14.88 ± 3.81 kg (range 10-20 kg) and 15.5 ± 3.8 mm (median 16 mm), respectively. A UAS was used in 15 out of 16 (93.8%) procedures. SFS was achieved in 81.3% of cases after the first procedure and 100% after auxiliary procedures. Postoperative urinary tract infections with fever (Clavien II) were observed in two (12.5%) patients. Hydrocalyx (Clavien IIIb) was noted in one (6.3%) patient. Patients with stones located in the lower polar calices (p = 0.024) and with mixed composition (p = 0.036) had a greater prevalence of complications than those with calculi of other compositions located in other sites. After a mean follow-up of 22.4 months no cases of ureteral strictures or vesicoureteral reflux were observed (Table).

DISCUSSION

The current findings support previous evidence showing safety and efficacy of RIRS with use of the UAS in pre-stented very young children. In our experience RIRS seems to be an effective and safe option with a stone-free rate of 81.3% and only 1 severe complication (Clavien-Dindo grade IIIb) and no long-term complications. This study is, to date, the first to examine the safety and efficacy of RIRS using UAS for the treatment of intrarenal stones in a selected cohort of pre-school patients weighing <20 kg.

CONCLUSIONS

RIRS using UAS is an effective and safe procedure for treating kidney stones in pre-school patients weighing <20 kg without complications at both short and long term follow up. Stones of mixed composition located in the lower polar calices are associated with a greater risk of postoperative complications.

New anthropometric classification scheme of preoperative nutritional status in children: a retrospective observational cohort study

OBJECTIVE

WHO uses anthropometric classification scheme of childhood acute and chronic malnutrition based on low body mass index (BMI) ('wasting') and height for age ('stunting'), respectively. The goal of this study was to describe a novel two-axis nutritional classification scheme to (1) characterise nutritional profiles in children undergoing abdominal surgery and (2) characterise relationships between preoperative nutritional status and postoperative morbidity.

DESIGN

This was a retrospective observational cohort study.

SETTING

The setting was 50 hospitals caring for children in North America that participated in the American College of Surgeons National Surgical Quality Improvement Program Paediatric from 2011 to 2013.

PARTICIPANTS

Children >28 days who underwent major abdominal operations were identified.

INTERVENTIONS/MAIN PREDICTOR

The cohort of children was divided into five nutritional profile groups based on both BMI and height for age Z-scores: (1) underweight/short, (2) underweight/tall, (3) overweight/short, (4) overweight/tall and (5) non-outliers (controls).

MAIN OUTCOME MEASURES

Multiple variable logistic regressions were used to quantify the association between 30-day morbidity and nutritional profile groups while adjusting for procedure case mix, age and American Society of Anaesthesiologists class.

RESULTS

A total of 39 520 cases distributed as follows: underweight/short (656, 2.2%); underweight/tall (252, 0.8%); overweight/short (733, 2.4%) and overweight/tall (1534, 5.1%). Regression analyses revealed increased adjusted odds of composite morbidity (35%) and reintervention events (75%) in the underweight/short group, while overweight/short patients had increased adjusted odds of composite morbidity and healthcare-associated infections (43%), and reintervention events (79%) compared with controls.

CONCLUSION

Stratification of preoperative nutritional status using a scheme incorporating both BMI and height for age is feasible. Further research is needed to validate this nutritional risk classification scheme for other surgical procedures in children.

Evaluating the Rule of 10s in Cleft Lip Repair: Do Data Support Dogma?

BACKGROUND

Cleft lip represents one of the most common birth defects in the world. Although the timing of cleft lip repair is contingent on a number of factors, the "rule of 10s" remains a frequently quoted safety benchmark. Initially reported by Wilhelmsen and Musgrave in 1966 and modified by Millard in 1976, this rule referred to performing surgery once patients had reached cutoffs in weight, hemoglobin, and age/leukocyte count. Despite significant advances in both surgical and anesthetic technique, the oft-quoted "rule of 10s" has not been systematically investigated since its inception.

METHODS

Patients who underwent primary cleft lip repair were identified from the National Surgical Quality Improvement Program Pediatric database. Multivariate logistic regression models were used to determine the independent effect of each rule of 10 metric or violation of the rule of 10s as a whole on postoperative complications, and to determine independent risk factors for complications in cleft lip surgery.

RESULTS

One thousand three hundred thirteen patients met inclusion criteria, with a 3.6 percent complication rate. Of the included patients, 151 (11.5 percent) violated at least one facet of the rule of 10s. Other than patient weight, neither the rule of 10s nor any individual metric was significantly predictive of postoperative complications.

CONCLUSIONS

Since its introduction nearly a half century ago, the risks associated with performing surgery in patients who violate the rule of 10s has undergone dramatic reductions. This analysis highlights the need to continually validate and evaluate dogma as the field continues to advance.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Influence of weight at enterostomy reversal on surgical outcomes in infants after emergent neonatal stoma creation

PURPOSE

Neonates after emergent enterostomy creation frequently require reversal at low weight because of complications including cholestasis, dehydration, dumping, failure to thrive, and failure to achieve enteral independence. We investigated whether stoma reversal at low weight (< 2.5kg) is associated with poor surgical outcomes.

METHODS

Patients who underwent enterostomy reversal from 2005 to 2013 at less than 6months old were identified in our institutional database. Only patients who underwent emergent enterostomy creation (i.e. for necrotizing enterocolitis or spontaneous perforation) were included. Demographics, disease process, comorbidities, stoma type, reversal indication, operative details, and complications were examined. Patients were categorized by weight at reversal of less than 2kg, 2.01-2.5kg, 2.51-3.5kg, and greater than 3.5kg. Data were analyzed using univariable and multivariable regression with significance level of p<0.05. The primary outcome examined was major morbidity, defined as the presence of anastomotic leak, obstruction, hernia, EC fistula, perforation, wound infection, sepsis, or death.

RESULTS

Eighty-nine patients met inclusion criteria. Demographics (sex, ethnicity, surgical disease process, reversal indication, and ASA score) were similar. The lowest weight group had lower gestational age (p<0.001) and birth weight (p=0.005), and contained a higher proportion of jejunostomies to ileostomies (p=0.013). On univariable analysis, only incisional hernia was significantly different as a complication between weight groups. On multivariable analysis controlling for gestational age and ASA, there was no significant difference in odds of major operative morbidity between groups.

CONCLUSIONS

Enterostomy reversal at lower weight may not be associated with increased risk of perioperative complications. Early stoma reversal may be acceptable when required for progression of neonatal care.

LEVEL OF EVIDENCE

Level III, Treatment Study (Retrospective comparative study).

Obesity and single-incision laparoscopic appendectomy in children

BACKGROUND

Single-incision laparoscopic appendectomy (SILA) has emerged as a less-invasive alternative to conventional laparoscopy. The purpose of this study was to assess the impact of body habitus on outcomes after SILA in the pediatric population.

METHODS

A retrospective review of 413 patients who underwent SILA from 2012 to 2015 was performed. Body mass index (BMI) was calculated, and the BMI percentile was obtained per Center for Disease Control guidelines. Standard definitions for overweight (BMI 85th-94th percentile) and obese (BMI > 95th percentile) were used. General demographic and outcome data were analyzed.

RESULTS

SILA was performed in 413 patients during the study period, of which 66.3% were normal weight, 16% were overweight, and 17.7% were obese. There were no significant differences in age at presentation, time to diagnosis, or intraoperative classification of appendicitis. There were no significant differences in operative time (27.0 ± 9.1 versus 27 ± 9.8 versus 28.4 ± 9.4 min, P = 0.514), postoperative length of stay (0.97 ± 1.65 versus 1.53 ± 4.15 versus 1.14 ± 2.27 d, P = 0.214), 30-d surgical site infections (6.9% versus 12.1% versus 8.2%, P = 0.377), emergency department visits (8.4% versus 10.6% versus 11%, P = 0.726), or readmissions (4.7% versus 4.1% versus 4.5%, P = 0.967) among normal, overweight, and obese groups.

CONCLUSIONS

Our results indicate that obesity does not significantly impact outcomes after SILA. SILA can be performed in overweight and obese children with no significant difference in operative time, length of stay, or incidence of surgical site infection. SILA should continue to be offered to overweight and obese children.

Preoperative risk assessment in children undergoing major urologic surgery

BACKGROUND

Preoperative risk assessment is standard in adult surgery, but often these risk assessments cannot be applied to children. Previous studies emphasize the differences between pediatric and adult populations and variability by surgical procedure types.

OBJECTIVE

We investigated preoperative risk factors for several outcomes in children undergoing major urologic surgery using the National Surgical Quality Improvement Program (NSQIP) Pediatric.

STUDY DESIGN

A cohort of 2-18-year-old children who underwent major urologic surgery was identified by Current Procedure Terminology (CPT) codes in the 2012-2013 NSQIP-Pediatric. The NSQIP-Pediatric prospectively collects standardized and validated data from 61 sites on preoperative, operative, and 30-day postoperative variables. Urologic surgeries involving dissection of the peritoneal or extraperitoneal space were included. Patients undergoing pure genitourinary surgery were analyzed separately from those with bowel involvement to improve homogeneity. Postoperative outcomes including hospital length of stay and 30-day infective complications, non-infective complications, unplanned reoperation and readmissions were evaluated by fitting multivariable logistic regression models.

RESULTS

A total of 2601 patients were identified, of whom 399 (15.3%) underwent bowel-involved surgery and 2202 (84.7%) underwent pure genitourinary surgery. Patients in the bowel-involved group were significantly older with more comorbidity. Postoperative complications, unplanned return to operating room, hospital length of stay and readmission rates were all significantly worse in the bowel-involved group. In the pure genitourinary group, older age and white race improved some outcomes, while American Society of Anesthesia (ASA) class ≥ 3, total operation time, obesity, pulmonary risk factors, preoperative renal disease, developmental delay, structural central nervous system abnormality, and supplemental nutrition independently predicted at least one negative outcome (Table).

DISCUSSION

Consistent with previous research on reconstructive surgery, we identified a significant difference in patient age, surgery details, comorbidity, and increased complications for patients undergoing urologic surgery with bowel involvement compared with pure genitourinary surgery. Focusing solely on pure genitourinary surgery, we identified predictors of outcomes. Identification of these factors in pediatric urology is novel and only recently possible with the availability of the NSQIP-Pediatric.

CONCLUSION

Using the NSQIP-Pediatric, we confirmed differences in complication rates for major urologic surgeries, with and without bowel involvement in a national sample. Preoperative risk characteristics were also identified for patients undergoing pure genitourinary surgery. Further investigation into these relationships is necessary to better elucidate their clinical significance with the goal of improving surgical planning, postoperative care, and family counseling.

Variation in intraoperative and postoperative red blood cell transfusion in pediatric surgery

BACKGROUND

Intraoperative and postoperative red blood cell (RBC) transfusions are relatively frequent events tracked in the American College of Surgeons' National Surgical Quality Improvement Program-Pediatric (ACS-NSQIP-P). This study sought to quantify variation in RBC transfusion practices among hospitals.

STUDY DESIGN AND METHODS

This is an observational study of children older than 28 days who underwent a general, neurologic, urologic, otolaryngologic, plastic, or orthopedic operation at 50 hospitals in participating in the ACS-NSQIP-P during 2011 to 2012. The primary outcome was whether or not a RBC transfusion was administered from incision time to 72 hours postoperatively. Transfusions of fresh-frozen plasma, cryoprecipitate, and platelets were excluded from data abstraction due the rarity of their administration. A multivariate hierarchical risk-adjustment model estimated the risk-adjusted hospital RBC transfusion odds ratio (OR) and designated hospitals by transfusion practice.

RESULTS

The mean RBC transfusion rate was 1.5%. Five preoperative variables were associated with greater than threefold increased odds of having an intraoperative or postoperative RBC transfusion; young age; 29 days to 1 year (OR, 5.9; p < 0.001) and 1 to 2 years (OR, 3.4; p < 0.001); American Society of Anesthesiologists Class IV (OR, 3.2; p < 0.001); procedure linear risk (OR, 3.1; p < 0.001); preoperative septic shock (OR, 14.5; p < 0.001); and preoperative cardiopulmonary resuscitation (OR, 8.1; p < 0.001). Twenty-five hospitals had RBC transfusion practices significantly different than risk-adjusted mean (17 higher and eight lower).

CONCLUSION

Intraoperative and postoperative RBC transfusion practices vary widely among hospitals after controlling for patient and procedural characteristics.

Is undernutrition prognostic of infection complications in children undergoing surgery? A systematic review

BACKGROUND

Healthcare-associated infections are costly and are increasingly viewed as an indicator of the quality of care. Although strategies to reduce infections have become widespread, few studies have formally investigated the role of undernutrition on the development of infection-related complications in children after surgery.

AIM

To perform a systematic review of the literature to determine if undernutrition is prognostic of postoperative infection complications in children.

METHODS

Electronic bibliographic and research databases were searched from 1950 to 2014. Inclusion criteria were studies in children (age <18 years) evaluating pre-operative nutritional status and reporting postoperative infection complications. Quality assessment was performed independently by two reviewers, with disagreements resolved by a third reviewer. The quality of the evidence was judged to be low in the majority of studies.

FINDINGS

Ten cohort and two case-control studies met the inclusion criteria. Five studies reported an outcome combining infection-related complications, with the remainder reporting individual infection complications. Six studies reported surgical site infection (SSI) alone or in combination with other infection complications. Direct comparison between studies was difficult due to clinical and diagnostic heterogeneity. Unadjusted analyses (for patient or clinical variables) were suggestive of a relationship between undernutrition and infection complications. In studies controlling for other variables, the analyses did not remain significant for SSI.

CONCLUSION

There was low-quality evidence that undernutrition may be predictive of postoperative infection complications in children, with the exception of SSI. However, inconsistencies in nutritional and outcome assessments made it difficult to draw conclusions. Larger, high-quality studies are warranted to further investigate a potential prognostic relationship.

The impact of obesity on laparoscopic appendectomy: Results from the ACS National Surgical Quality Improvement Program pediatric database

BACKGROUND

Childhood obesity is a worsening epidemic. Little is known about the impact of elevated BMI on perioperative and postoperative complications in children who undergo laparoscopic surgery. The purpose of this study was to examine the effects of obesity on surgical outcomes in children using laparoscopic appendectomy as a model for the broader field of laparoscopic surgery.

STUDY DESIGN

Using the Pediatric National Surgical Quality Improvement Program (NSQIP) data from 2012, patients aged 2-18years old with acute uncomplicated and complicated appendicitis who underwent laparoscopic appendectomy were identified. Children with a body mass index (BMI)≥95th percentile for their age and gender were considered obese. Primary outcomes, including overall morbidity and wound complications, were compared between nonobese and obese children. Multivariate regression analysis was conducted to identify the impact of obesity on outcome.

RESULTS

A total of 2812 children with acute appendicitis who underwent appendectomy were included in the analysis; 22% were obese. Obese children had longer operative times but did not suffer increased postoperative complications when controlling for confounders (OR 1.3, 95% CI: 0.83-0.072 for overall complications, OR 1.3, 95% CI: 0.84-1.95 for wound complications).

CONCLUSIONS

Obesity is not an independent risk factor for postoperative complications following laparoscopic appendectomy. Although operative times are increased in obese children, obesity does not increase the likelihood of 30-day postoperative complications.

Association of BMI and pediatric urologic postoperative events: Results from pediatric NSQIP

BACKGROUND

Elevated body mass index (BMI) is a well-known risk factor for perioperative complications in adults, but has not been investigated in children undergoing urologic procedures. Given the low rate of complications associated with urologic surgery, a large sample is required for their characterization, but BMI is frequently not available in administrative databases. Here we report results from the first nationally based, prospectively assembled cohort analyzed with respect to the association of BMI with 30-day postoperative events for pediatric urologic procedures.

OBJECTIVE

To determine the association of elevated BMI with overall 30-day postoperative events and wound complications in a large national sample of children undergoing urologic procedures.

STUDY DESIGN

We queried the 2012 Pediatric National Surgical Quality Improvement Program database (NSQIP), defining obesity as a BMI above the 95th percentile and overweight above the 85th percentile, per CDC definitions. We used BMI <85th percentile as a referent group. Complications were collected within 30 days of the procedure. Comorbidity was classified on a linear scale using a validated pediatric-specific comorbidity score, and procedures were classified as genital, abdominal without bowel involvement, or abdominal with bowel involvement. Univariate and multivariate logistic models were used to test significance of associations.

RESULTS

2871 patients aged 2-18 years were analyzed. Of these, 420 (14.6%) were overweight and 440 (15.3%) were obese. A summary of 30-day events and complications is shown in the structured abstract table. On multivariate analysis adjusting for age, gender, class of procedure, and comorbidity, BMI remained a significant risk factor for 30-day events when comparing BMI ≥85th percentile to BMI <85th percentile (OR 1.36, 95% CI 1.03-1.8, p = 0.035). An exploratory subgroup analysis examining the rate of wound complications demonstrated an odds ratio of 2.36 (95% CI 1.28-4.35, p = 0.006) for BMI >85th percentile on multivariate analysis.

DISCUSSION

Overweight/obese status increased the odds of overall complications by 36%, and of wound complications by 140%. In adults there is a known profound effect of body composition on wound complications, but in children this association is less clear, and has not been studied in the pediatric urologic literature on a large scale. The mechanisms linking BMI to pediatric postoperative complications are unclear, but cytokine mechanisms or changes in the response to inflammation have been postulated. Limitations of this study include restriction to those urologic procedures included in ACS-NSQIPP and sorted into broad general categories. We did not control for secondary procedures. BMI/BMI percentile may not be appropriate measures of body composition in patients with atypical body habitus or proportions (e.g. myelomeningocele).

CONCLUSION

BMI in the pediatric NSQIP urologic population was found to be associated with overall complication after adjustment for case type and preoperative comorbidity in a large national sample assembled for assessment of perioperative outcomes. An exploratory analysis uncovered more than two-fold increase in odds of wound complication in obese/overweight patients compared with a normal weight referent population. These results may be useful in preoperative counseling patients regarding perioperative risk.