Validation of the American College of Surgeons National Surgical Quality Improvement Program Risk Model for Patients Undergoing Panniculectomy

Hope for the best, but prepare for the worst - Diagnostic accuracy of the American College of Surgeons National Surgical Quality Improvement Program - Risk model for patients undergoing abdominoplasty after massive weight loss - Results from a Retrospective Cohort Study

Background

This study aimed to validate the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) risk calculator for predicting outcomes in patients undergoing abdominoplasty after massive weight loss.

Methods

Patients' characteristics, pre-existing comorbidities and adverse outcomes in our department from 2013 to 2023 were collected retrospectively. Adverse events were defined according to ACS-NSQIP standards and predicted risks were calculated manually using the ACS-NSQIP risk calculator. Binary logistic regression and the Brier score were used to assess the diagnostic accuracy of the model.

Results

Among the 337 individuals who underwent abdominoplasty, 251 had achieved significant weight loss before surgery. After excluding 46 cases due to incomplete data, 205 cases remained for analysis. There were 20% cases of serious complications, 26.3% of some complications, 10.2% of readmissions, 18.8% returned to the operating theatre, 15.6% of surgical site infections and 0.5% each of pneumonia and venous thromboembolism. Although the calculator predicted a 1.5% discharge rate to nursing or rehabilitation facilities and a 0.1% rate of sepsis, neither outcome was observed. Elevated American Society of Anesthesiologists (ASA) status was significantly associated with a higher complication rate, except for surgical site infections (SSI) (p = 0.06). Additionally, an elevated Body Mass Index (BMI) before post-bariatric surgery and a higher resection weight were both associated with increased rates of return to the operating theatre (p = 0.01) and serious complications (p = 0.01). Predicted complication rates (0.1%-8.6%) underestimated actual complication rates (0.5%-26.3%). The Brier scores did not differ significantly from the null model for any outcomes except for general complications (p = 0.001) and logistic regression models demonstrated low sensitivity (0.0-9.8%) and weak odds ratios (1.28-1.46), indicating limited reliability.

Conclusion

The ACS-NSQIP risk calculator does not reliably predict adverse outcomes in this patient cohort.

The Impact of Obesity on Plastic Surgery Outcomes: A Systematic Review and Meta-analysis

BACKGROUND

Obesity is a potential risk factor for complications in plastic surgeries. However, the data presented by primary studies are contradictory.

OBJECTIVES

The aim of this study was to summarize and clarify the divergences in the literature to provide a better understanding of the impact of obesity in different plastic surgery procedures.

METHODS

We conducted a systematic review and meta-analysis of the impact of obesity on plastic surgery outcomes. Searches were conducted in MEDLINE, LILACS, SciELO, Scopus, Embase, Web of Science, Opengrey.eu, and the Cochrane Database of Systematic Reviews. The primary outcomes assessed were surgical complications, medical complications, and reoperation rates. The secondary outcome assessed was patient satisfaction. Subgroup analysis was performed to investigate the impact of each BMI category on the outcomes.

RESULTS

Ninety-three articles were included in the qualitative synthesis, and 91 were used in the meta-analysis. Obese participants were 1.62 times more likely to present any of the primary outcomes (95% CI, 1.48-1.77; P < 0.00001). The highest increase in risk among plastic surgery types was observed in cosmetic procedures (risk ratio [RR], 1.80; 95% CI, 1.43-2.32; P < 0.00001). Compared with normal-weight participants, overweight participants presented a significantly increased RR for complications (RR, 1.16; 95% CI, 1.07-1.27; P = 0.0004). Most authors found no relation between BMI and overall patient satisfaction.

CONCLUSIONS

Obesity leads to more complications and greater incidence of reoperation compared with nonobese patients undergoing plastic surgeries. However, this effect is not evident in reconstructive surgeries in areas of the body other than the breast.

Evaluating the Inaccuracy of the National Surgical Quality Improvement Project Surgical Risk Calculator in Plastic Surgery: A Meta-analysis of Short-Term Predicted Complications

BACKGROUND

Preoperative surgical risk assessment is a major component of clinical decision making. The ability to provide accurate, individualized risk estimates has become critical because of growing emphasis on quality metrics benchmarks. The American College of Surgeons National Surgical Quality Improvement Project (NSQIP) Surgical Risk Calculator (SRC) was designed to quantify patient-specific risk across various surgeries. Its applicability to plastic surgery is unclear, however, with multiple studies reporting inaccuracies among certain patient populations. This study uses meta-analysis to evaluate the NSQIP SRC's ability to predict complications among patients having plastic surgery.

METHODS

OVID MEDLINE and PubMed were searched for all studies evaluating the predictive accuracy of the NSQIP SRC in plastic surgery, including oncologic reconstruction, ventral hernia repair, and body contouring. Only studies directly comparing SCR predicted to observed complication rates were included. The primary measure of SRC prediction accuracy, area under the curve (AUC), was assessed for each complication via DerSimonian and Laird random-effects analytic model. The I2 statistic, indicating heterogeneity, was judged low (I2 < 50%) or borderline/unacceptably high (I2 > 50%). All analyses were conducted in StataSE 16.1 (StataCorp LP, College Station, Tex).

RESULTS

Ten of the 296 studies screened met criteria for inclusion (2416 patients). Studies were classified as follows: (head and neck: n = 5, breast: n = 1, extremity: n = 1), open ventral hernia repair (n = 2), and panniculectomy (n = 1). Predictive accuracy was poor for medical and surgical complications (medical: pulmonary AUC = 0.67 [0.48-0.87], cardiac AUC = 0.66 [0.20-0.99], venous thromboembolism AUC = 0.55 [0.47-0.63]), (surgical: surgical site infection AUC = 0.55 [0.46-0.63], reoperation AUC = 0.54 [0.49-0.58], serious complication AUC = 0.58 [0.43-0.73], and any complication AUC = 0.60 [0.57-0.64]). Although mortality was accurately predicted in 2 studies (AUC = 0.87 [0.54-0.99]), heterogeneity was high with I2 = 68%. Otherwise, heterogeneity was minimal (I2 = 0%) or acceptably low (I2 < 50%) for all other outcomes.

CONCLUSIONS

The NSQIP Universal SRC, aimed at offering individualized quantifiable risk estimates for surgical complications, consistently demonstrated poor risk discrimination in this plastic surgery-focused meta-analysis. The limitations of the SRC are perhaps most pronounced where complex, multidisciplinary reconstructions are needed. Future efforts should identify targets for improving SRC reliability to better counsel patients in the perioperative setting and guide appropriate healthcare resource allocation.

Inaccurate Risk Assessment by the ACS NSQIP Risk Calculator in Aortic Surgery

OBJECTIVES

The aim of this retrospective study was to assess the predictive performance of the American College of Surgeons (ACS) risk calculator for aortic aneurysm repair for the patient population of a Dutch tertiary referral hospital.

METHODS

This retrospective study included all patients who underwent elective endovascular or open aortic aneurysm repair at our institution between the years 2013 and 2019. Preoperative patient demographics and postoperative complication data were collected, and individual risk assessments were generated using five different current procedural terminology (CPT) codes. Receiver operating characteristic (ROC) curves, calibration plots, Brier scores, and Index of Prediction Accuracy (IPA) values were generated to evaluate the predictive performance of the ACS risk calculator in terms of discrimination and calibration.

RESULTS

Two hundred thirty-four patients who underwent elective endovascular or open aortic aneurysm repair were identified. Only five out of thirteen risk predictions were found to be sufficiently discriminative. Furthermore, the ACS risk calculator showed a structurally insufficient calibration. Most Brier scores were close to 0; however, comparison to a null model though IPA-scores showed the predictions generated by the ACS risk calculator to be inaccurate. Overall, the ACS risk calculator showed a consistent underestimation of the risk of complications.

CONCLUSIONS

The ACS risk calculator proved to be inaccurate within the framework of endovascular and open aortic aneurysm repair in our medical center. To minimize the effects of patient selection and cultural differences, multicenter collaboration is necessary to assess the performance of the ACS risk calculator in aortic surgery.

Predictive Accuracy of the American College of Surgeons Risk Calculator in Patients Undergoing Major Lower Extremity Amputation

BACKGROUND

The American College of Surgeons Risk Calculator (ACS-RC) provides an assessment of a patient's risk of 30-day postoperative complications. The Surgeon Adjusted Risk (SAR) parameter of the calculator allows for ad hoc adjustment of risk based on risk factors not considered by the model. This study aims to evaluate the predictive accuracy of the ACS-RC in vascular surgery patients undergoing major lower-extremity amputation (LEA) and identify additional risk factors that warrant use of the SAR parameter.

METHODS

This is a retrospective study of 298 sequential amputations at a single institution. At the population level, the mean of predicted 30-day outcomes from the ACS-RC with a SAR score of 1 (no adjustment necessary) and 2 (risk somewhat higher than estimate) were compared to the rate of observed outcomes. Predictive accuracy at the individual level was completed using receiver operating curve area under the curve (AUC). Logistic regression with respect to mortality was performed over variables not considered by the ACS-RC. Efficacy of selectively utilizing the SAR parameter in predicting mortality was analyzed with a stratified analysis in which patients with risk factors significant for mortality were assigned increased risk.

RESULTS

At the population level, ACS-RC grossly underpredicted serious complications, SSI, VTE, and unplanned RTOR, while overpredicting mortality and cardiac complications. At the individual level, SAR1 was more predictive for serious complications (AUC = 0.624), SSI (AUC = 0.610), and unplanned RTOR (AUC = 0.541). Conversely, SAR2 was more predictive for mortality (AUC = 0.709), cardiac complications (AUC = 0.561), and VTE (AUC = 0.539). Logistic regression identified history of CVA with a residual deficit (OR = 4.61, P = 0.033) and ischemic rest pain without tissue loss (OR = 4.497, P = 0.047) as independent risk factors for postoperative mortality. Stratified analysis with utilization of the SAR2 based on the 2 independent risk factors improved AUC in predicting mortality (AUC 0.792 from 0.709).

CONCLUSIONS

Major LEAs are associated with high perioperative morbidity and mortality. In a veteran population, the ACS-RC showed mixed predictability at the population level and fair predictability at the individual level with regards to postoperative outcomes. Rest pain without tissue loss and history of CVA with residual deficit were identified as risk factors for postoperative mortality. Although ad hoc adjustment with the subjective SAR modifier based on the presence of these 2 risk factors increased the calculator's accuracy, this study highlights some potential limitations of the ACS-RC when applied to vascular surgery patients undergoing major LEA.

Evaluating Outcomes and Weight Loss After Panniculectomy

OBJECTIVE

The objective of this study was to evaluate long-term outcomes and weight loss after panniculectomy.

METHODS

A retrospective chart review study was performed on 225 consecutive patients who had undergone panniculectomy from 2002 and 2020. Demographic variables including smoking status, medical comorbidities, and prior history of weight loss/bariatric surgery were collected for 173 patients. Preoperative and postoperative body mass index (BMI) were calculated in addition to postoperative outcomes.

RESULTS

The study population was 85% female with a mean age of 57 years and an average follow-up of 3.9 years. Relevant comorbidities included obesity (88%), hypertension (65%), diabetes (37%), and smoking (8%), and the majority (53%) of patients had undergone prior bariatric surgery. The overall complication rate was 40%. Twenty percent of patients required reoperation or readmission, and 20% had minor complications addressed in an outpatient setting. Patients who had higher preoperative BMI experienced a significant long-term reduction in BMI. In addition, patients who did not undergo prior bariatric surgery tended to lose weight more often and by larger amounts than patients who had prior bariatric surgery (71.6% vs 57.6, P = 0.023). Complications were not uncommon and included infection (17%), delayed wound healing (16%), seroma (8%), and hematoma (3%). Patients who had prior bariatric surgery were at reduced risk of any complication (P = 0.012). Smoking increased the incidence of infection (38.5% of smokers vs 15.6% of nonsmokers, P = 0.039). Concomitant hernia repair increased the risk of overall complications (64.3% vs 35.9%, P = 0.003) and delayed wound healing (39.2% vs 11.7%, P < 0.001). In the subgroup of patients who did not lose weight, a panniculus weight greater than 5 kg was associated with an increased complication rate (61.5% vs 27%, P = 0.03).

CONCLUSIONS

Patients who underwent a panniculectomy tended to lose weight postoperatively, particularly those who had not undergone previous bariatric surgery. Complications were not uncommon, especially in patients with a smoking history. Prior bariatric surgery patients had a significant decrease in postoperative complications but tended to lose less weight after panniculectomy than those without prior bariatric surgery. Concomitant hernia repair put patients at an increased risk of complications.