Assessing the predictive accuracy of the American College of Surgeons National Surgical Quality Improvement Project Surgical Risk Calculator in open ventral hernia repair

Hypoalbuminemia improves the ACS-NSQIP surgical risk calculator for gastrectomy

BACKGROUND

The ACS-NSQIP Surgical Risk Calculator (SRC) is used to predict surgical outcomes, but its accuracy in gastrectomy has been questioned.1,2 We investigated if adding hypoalbuminemia enhances its predictive ability in gastrectomy.

METHODS

We identified gastrectomy patients from the ACS-NSQIP database from 2005 to 2019. We constructed pairs of logistic regression models: one with the existing 21 preoperative risk factors from the SRC and another with the addition of hypoalbuminemia. We evaluated improvement using Likelihood Ratio Test (LRT), Brier scores, and c-statistics.

RESULTS

Of 18,070 gastrectomy patients, 34.5 ​% had hypoalbuminemia. Hypoalbuminemia patients had 2.34 higher odds of mortality and 1.79 higher odds of morbidity. Adding hypoalbuminemia to the RC model statistically improved predictions for mortality, cumulative morbidity, pulmonary, renal, and wound complications (LRT p ​< ​0.001). It did not improve predictions for cardiac complications (LRT p ​= ​0.11) CONCLUSION: Hypoalbuminemia should be considered as an additional variable to the ACS-NSQIP SRC for gastrectomy.

Staged abdominal wall reconstruction in the setting of complex gastrointestinal reconstruction

PURPOSE

Literature on one- versus two-staged abdominal wall reconstruction (AWR) with complex gastrointestinal reconstruction (GIR) is limited to single-arm case series with a focus on patients who complete all planned stages. Herein, we describe our experience with both one- and two-staged approaches to AWR/GIR, with attention to those who did not complete both intended stages.

METHODS

A retrospective review of prospectively collected data was conducted to identify patients who underwent a one- or two-stage approach to GIR/AWR from 2013 to 2020. The one-stage approach included GIR and definitive sublay mesh herniorrhaphy. The two-stage approach included Stage 1 (S1)-GIR and non-definitive herniorrhaphy and Stage 2 (S2)-definitive sublay mesh herniorrhaphy.

RESULTS

Fifty-four patients underwent GIR/AWR: 20 (37.0%) underwent a planned 1-stage operation while 34 (63.0%) underwent S1 of a planned 2-stage approach. Patients assigned to the 2-stage approach were more likely to be smokers, have a history of mesh infection, have an enterocutaneous fistula, and a contaminated wound class (p<0.05). Of the 34 patients who underwent S1, 12 (35.3%) completed S2 during the mean follow-up period of 44 months while 22 (64.7%) did not complete S2. Of these, 10 (45.5%) developed hernia recurrence but did not undergo S2 secondary to elective nonoperative management (40%), pending preoperative optimization (30%), additional complex GIR (10%), hernia-related incarceration requiring emergent surgery (10%), or unrelated death (10%). No differences in outcome including SSI, SSO, readmission, and recurrence were noted between the 12 patients who completed the two-stage approach and the 20 patients who completed a one-stage approach, despite increased risk factors for complications in the 2-stage group (p>0.05).

CONCLUSION

Planned two-stage operations for GIR/AWR may distribute operative complexity and post-operative morbidity into separate surgical interventions. However, many patients may never undergo the intended definitive S2 herniorrhaphy. Future evaluation of 1- versus 2-stage GIR/AWR is needed to clarify indications for each approach. This work must also consider the frequent deviations from intended clinical course demonstrated in this study.

Hernia-to-neck ratio is associated with emergent ventral hernia repair

BACKGROUND

The ratio of hernia size to fascial defect size, termed the hernia-to-neck ratio (HNR), has been proposed as a novel predictive factor for umbilical hernia complications. HNR ≥ 2.5 has been suggested to warrant surgery due to association with bowel strangulation, incarceration, and necrosis. The aim of this study was to evaluate the association between HNR and emergent ventral hernia repair at our institution.

METHODS

A retrospective cohort study was performed of consecutive patients with ventral hernias evaluated at a large safety-net hospital from 2017 to 2019. Patients who required emergent ventral hernia repair were compared to patients who did not require repair at latest follow-up. HNR was calculated using a previously described method: maximal hernia sac size and maximal fascial defect size (termed "hernia neck size") were measured in the sagittal plane on CT scan. Data are described as mean ± standard deviation and median (interquartile range).

RESULTS

A total of 166 patients were included: 84 (51%) required emergent hernia repair and 82 (49%) did not undergo repair. Median follow-up was 19 (8-27) months. Patient groups were similar except the emergent repair group had more males (50% vs. 34%, p = 0.03), umbilical hernias (93% vs. 56%, p < 0.01), recurrent hernias (31% vs. 15%, p < 0.01), and lower mean BMI (34.3 ± 9.9 vs. 39.1 ± 6.5, p < 0.01). Hernia sac size did not differ between groups (5.8 [3.8-8.4] cm vs. 6.1 [3.5-11.8] cm, p = 0.45). Hernia neck size was significantly smaller in the emergent repair group (1.5 [2.3-3.5] cm vs. 3.4 [1.8-6.2] cm, p < 0.01). Hernia-to-neck ratio was significantly higher in the emergent repair group (2.4 [1.8-3.1] vs. 1.7 [1.1-2.9], p < 0.01).

CONCLUSION

This study demonstrated an association between higher HNR and increased risk of emergent ventral hernia repair. Future studies will evaluate the use of HNR to risk-stratify patients with ventral hernias in a safety-net hospital.

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.

What is the Accuracy of the ACS-NSQIP Surgical Risk Calculator in Emergency Abdominal Surgery? A Meta-Analysis

BACKGROUND

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) surgical risk calculator provides an estimation of 30-d post-operative complications including mortality. This tool has the potential to both aid in decision-making for patients and their families and also in optimizing the clinical management of high-risk patients. However, it's utility in patients requiring emergency abdominal surgery has shown to be inconsistent outside of NSQIP participating institutions. This study undertook a meta-analysis to assess the calculator's accuracy in predicting mortality in these patients.

METHODS

A literature search of PubMed, Medline and Cochrane databases was conducted between October 2019 to April 2020. The PubMed, Medline and Cochrane Databases were searched for relevant studies. The search strategy included studies from January 2013 to April 2020. Studies including elective surgery were excluded. A random effects model was used and fitted using restricted maximum likelihood estimation. The O:E ratio was used to validate the calculator's accuracy in predicting mortality.

RESULTS

Six studies were included in the meta-analysis, with a total of 1835 patients undergoing emergency intra-abdominal surgery. The summary estimate of the O:E ratio of the ACS-NSQIP surgical risk calculator in predicting 30-d post-operative mortality was 1.06 (95% CI 0.74-1.51). There was significant heterogeneity between studies with a Cochrane Q of 11.96 (P = 0.04) and I² = 57.5%.

CONCLUSIONS

The ACS-NSQIP surgical risk calculator is a reliable predictor of mortality in this external cohort and has potential to be utilised in the multi-disciplinary care of patients undergoing emergency abdominal surgery.

A non-linear ensemble model-based surgical risk calculator for mixed data from multiple surgical fields

BACKGROUND

The misestimation of surgical risk is a serious threat to the lives of patients when implementing surgical risk calculator. Improving the accuracy of postoperative risk prediction has received much attention and many methods have been proposed to cope with this problem in the past decades. However, those linear approaches are inable to capture the non-linear interactions between risk factors, which have been proved to play an important role in the complex physiology of the human body, and thus may attenuate the performance of surgical risk calculators.

METHODS

In this paper, we presented a new surgical risk calculator based on a non-linear ensemble algorithm named Gradient Boosting Decision Tree (GBDT) model, and explored the corresponding pipeline to support it. In order to improve the practicability of our approach, we designed three different modes to deal with different data situations. Meanwhile, considering that one of the obstacles to clinical acceptance of surgical risk calculators was that the model was too complex to be used in practice, we reduced the number of input risk factors according to the importance of them in GBDT. In addition, we also built some baseline models and similar models to compare with our approach.

RESULTS

The data we used was three-year clinical data from Surgical Outcome Monitoring and Improvement Program (SOMIP) launched by the Hospital Authority of Hong Kong. In all experiments our approach shows excellent performance, among which the best result of area under curve (AUC), Hosmer-Lemeshow test ([Formula: see text]) and brier score (BS) can reach 0.902, 7.398 and 0.047 respectively. After feature reduction, the best result of AUC, [Formula: see text] and BS of our approach can still be maintained at 0.894, 7.638 and 0.060, respectively. In addition, we also performed multiple groups of comparative experiments. The results show that our approach has a stable advantage in each evaluation indicator.

CONCLUSIONS

The experimental results demonstrate that NL-SRC can not only improve the accuracy of predicting the surgical risk of patients, but also effectively capture important risk factors and their interactions. Meanwhile, it also has excellent performance on the mixed data from multiple surgical fields.

Surgical Predictive Model for Breast Cancer Patients Assessing Acute Postoperative Complications: The Breast Cancer Surgery Risk Calculator

BACKGROUND

Prognostic tools, such as risk calculators, improve the patient-physician informed decision-making process. These tools are limited for breast cancer patients when assessing surgical complication risk preoperatively.

OBJECTIVE

In this study, we aimed to assess predictors associated with acute postoperative complications for breast cancer patients and then develop a predictive model that calculates a complication probability using patient risk factors.

METHODS

We performed a retrospective cohort study using the National Surgical Quality Improvement Program (NSQIP) database from 2005 to 2017. Women diagnosed with ductal carcinoma in situ or invasive breast cancer who underwent either breast conservation or mastectomy procedures were included in this predictive modeling scheme. Four models were built using logistic regression methods to predict the following composite outcomes: overall, infectious, hematologic, and internal organ complications. Model performance, accuracy and calibration measures during internal/external validation included area under the curve, Brier score, and Hosmer-Lemeshow statistic, respectively.

RESULTS

A total of 163,613 women met the inclusion criteria. The area under the curve for each model was as follows: overall, 0.70; infectious, 0.67; hematologic, 0.84; and internal organ, 0.74. Brier scores were all between 0.04 and 0.003. Model calibration using the Hosmer-Lemeshow statistic found all p-values to be > 0.05. Using model coefficients, individualized risk can be calculated on the web-based Breast Cancer Surgery Risk Calculator (BCSRc) platform ( www.breastcalc.org ).

CONCLUSION

We developed an internally and externally validated risk calculator that estimates a breast cancer patient's unique risk of acute complications following each surgical intervention. Preoperative use of the BCSRc can potentially help stratify patients with an increased complication risk and improve expectations during the decision-making process.

Leveraging Decision Curve Analysis to Improve Clinical Application of Surgical Risk Calculators

BACKGROUND

Surgical risk calculators (SRCs) have been developed for estimation of postoperative complications but do not directly inform decision-making. Decision curve analysis (DCA) is a method for evaluating prediction models, measuring their utility in guiding decisions. We aimed to analyze the utility of SRCs to guide both preoperative and postoperative management of patients undergoing hepatopancreaticobiliary surgery by using DCA.

METHODS

A single-institution, retrospective review of patients undergoing hepatopancreaticobiliary operations between 2015 and 2017 was performed. Estimation of postoperative complications was conducted using the American College of Surgeons SRC [ACS-SRC] and the Predictive OpTimal Trees in Emergency Surgery Risk (POTTER) calculator; risks were compared with observed outcomes. DCA was used to model optimal patient selection for risk prevention strategies and to compare the relative performance of the ACS-SRC and POTTER calculators.

RESULTS

A total of 994 patients were included in the analysis. C-statistics for the ACS-SRC prediction of 12 postoperative complications ranged from 0.546 to 0.782. DCA revealed that an ACS-SRC-guided readmission prevention intervention, when compared with an all-or-none approach, yielded a superior net benefit for patients with estimated risk between 5% and 20%. Comparison of SRCs for venous thromboembolism intervention demonstrated superiority of the ACS-SRC for thresholds for intervention between 2% and 4% with the POTTER calculator performing superiorly between 4% and 8% estimated risk.

CONCLUSIONS

SRCs can be used not only to predict complication risk but also to guide risk prevention strategies. This methodology should be incorporated into external validations of future risk calculators and can be applied for institution-specific quality improvement initiatives to improve patient outcomes.

How to Develop a Risk Prediction Smartphone App

Purpose. Powered by big data, predictive models provide individualized risk stratification to inform clinical decision-making and mitigate long-term morbidity. We describe how to transform a large institutional dataset into a real-time, interactive clinical decision support mobile user interface for risk prediction. Methods. A clinical decision point ideal for risk stratification and modification was identified. Demographics, medical comorbidities, and operative characteristics were abstracted from the electronic medical record (EMR) using ICD-9 codes. Surgery-specific predictive models were generated using regression modeling and corroborated with internal validation. A clinical support interface was designed in partnership with an app developer, followed by subsequent beta testing and clinical implementation of the final tool. Results. Individual, specialty-specific, and preoperatively actionable models incorporating clustered procedural codes were created. Using longitudinal inpatient, outpatient, and office-based data from a large multicenter health system, all patient and operative variables were weighted according to ß-coefficients. The individual risk model parameters were incorporated into specialty-specific modules and implemented into an accessible iOS/Android compatible mobile application. Conclusions. As proof of concept, we provide a framework for developing a clinical decision support mobile user interface, through the use of clinical and administrative longitudinal data. Point-of-care applications, particularly ones designed with implementation and actionability in mind, have the potential to aid clinicians in identifying and optimizing risk factors that impact the outcome of interest's occurrence, thereby enabling clinicians to take targeted risk-reduction actions. In addition, such applications may help facilitate counseling, informed consent, and shared decision-making, leading to improved patient-centered care.

Risk-adjustment models in patients undergoing head and neck surgery with reconstruction

BACKGROUND

With the current focus on value-based outcomes and reimbursement models, perioperative risk adjustment is essential. Specialty surgical outcomes are not well predicted by the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP); the Head and Neck-Reconstructive Surgery NSQIP was created as a specialty-specific platform for patients undergoing head and neck surgery with flap reconstruction. This study aims to investigate risk prediction models in these patients.

METHODS

The Head and Neck-Reconstructive Surgery NSQIP collected data on patients undergoing head and neck surgery with flap reconstruction from August 1, 2012 to October 20, 2016. Multivariable logistic regression models were created for 9 outcomes (postoperative ventilator dependence, pneumonia, superficial recipient surgical site infection, presence of tracheostomy/nasoenteric (NE)/gastrostomy/gastrojejunostomy(G/GJ) tube 30 days postoperatively, conversion from NE to G/GJ tube, unplanned return to the operating room, length of stay > 7 days). External validation was completed with a more contemporary cohort.

RESULTS

A total of 1095 patients were included in the modelling cohort and 407 in the validation cohort. Models performed well predicting tracheostomy, NE, G/GJ tube presence at 30 days postoperatively and conversion from NE to G/GJ tube (c-indices = 0.75-0.91). Models for postoperative pneumonia, superficial recipient surgical site infection, ventilator dependence > 48 h, and length of stay > 7 days were fair (concordance [c]-indices = 0.63-0.69). The predictive model for unplanned return to the operating room was poor (c-index = 0.58).

CONCLUSIONS AND RELEVANCE

Reliable and discriminant risk prediction models were able to be created for postoperative outcomes using the specialty-specific Head and Neck-Reconstructive Surgery Specific NSQIP.

Evaluation of the Performance of ACS NSQIP Surgical Risk Calculator in Emergency General Surgery Patients

The ACS NSQIP Surgical Risk Calculator is designed to estimate the chance of an unfavorable outcome after surgery. Our goal was to evaluate the accuracy of the calculator in our emergency general surgery population. Surgical outcomes were compared to predicted risk. The risk was calculated with surgeon adjustment scores (SASs) of 1 (no adjustment), 2 (risk somewhat higher), and 3 (risk significantly higher than estimate). Two hundred and twenty-seven patients met the inclusion criteria. An SAS of 1 or 2 accurately predicted risk of mortality (5.7% and 8.5% predicted versus 7.9% actual), whereas a risk adjustment of 3 indicated significant overestimation of mortality rate (14.8% predicted). There was good overall prediction performance for most variables with no clear preference for SAS 1, 2, or 3. Poor correlation was seen with SSI, urinary tract infection, and length of stay variables. The ACS NSQIP Surgical Risk Calculator yields valid predictions in the emergency general surgery population, and the data support its use to inform conversations about outcome expectations.

Análisis multicéntrico del reparo de la hernia ventral en instituciones de IV nivel, 2015-2019

Introducción. La cirugía de hernia ventral implica una situación de complejidad, dadas las múltiples variables que se deben controlar para estimar los posibles factores determinantes del éxito quirúrgico y la aparición de complicaciones. Según la literatura científica mundial, la incidencia de hernia ventral se estima entre el 10 y el 15 %, y la tasa promedio de complicaciones de esta cirugía varía entre el 10 y el 37 %. El objetivo del presente estudio fue describir la experiencia y los resultados de la cirugía de hernia ventral en dos instituciones de IV nivel, en el periodo de enero de 2015 a marzo de 2019. Métodos. Se trata de un estudio observacional, descriptivo y de cohorte histórica, de pacientes mayores de edad sometidos a corrección de hernia ventral en la Clínica Colsanitas en los últimos cinco años. Los datos se tomaron del registro estadístico de las instituciones en mención. Resultados. Se incluyeron 612 pacientes en un periodo de cinco años, la mayoría de los cuales era de sexo femenino, con sobrepeso, y predominantemente, con defectos combinados mediales; la tasa general de complicaciones fue del 20 % y, el porcentaje de infección del sitio operatorio, de 9 %; para el desarrollo de esta infección, la técnica de separación de componentes se encontró como un factor de riesgo (p=0,01; RR=2,9; IC 95% 1,32-6,5). En este estudio, no se analizó la recidiva como factor de los diferentes resultados. Conclusiones. Existen pocos datos en la literatura nacional sobre los resultados de este tipo de procedimiento quirúrgico. Es por ello que se procuró brindar a la comunidad científica los resultados de morbimortalidad de esta muestra de pacientes intervenidos por hernia ventral en los últimos cinco años.

The impact of weight change on intra-abdominal and hernia volumes

BACKGROUND

Weight loss is often encouraged or required before open ventral hernia repair. This study evaluates the impact of weight change on total, intra-abdominal, subcutaneous, and hernia volume.

METHODS

Patients who underwent open ventral hernia repair from 2007 to 2018 with two preoperative computed tomography scans were identified. Scans were reviewed using 3D volumetric software. Demographics, operative characteristics, and outcomes were evaluated. The impact of weight change on intra-abdominal, subcutaneous, and hernia volume was assessed using Spearman's correlation coefficients and linear regression models.

RESULTS

A total of 250 patients met the criteria with a mean defect area of 155.6 ± 155.4 cm², subcutaneous volume of 6,800.0 ± 3,868.8 cm³, hernia volume of 915.7 ± 1,234.5 cm³, intra-abdominal volume equaling 4,250.2 ± 2,118.1 cm³, and time between computed tomography scans 13.9 ± 11.0 months. Weight change was associated with change in hernia, intra-abdominal, total, and subcutaneous volume (Spearman's correlation coefficients 0.17, 0.48, 0.51, 0.45, respectively, P ≤ 0.03 all values) and not associated in hernia length, width, or area (P ≥ 0.18 all values). A Δ5 kg was significantly associated with Δintra-abdominal volume (164.1 ± 30.0 cm³/Δ5 kg,P < .0001), Δtotal volume (209.9 ± 33.0 cm³/Δ5 kg, P < .0001), and Δsubcutaneous volume (234.4 ± 50.8 cm³/Δ5 kg, P < .0001). Per Δ5 kg, male patients had more than double the Δintra-abdominal, Δtotal, and Δsubcutaneous volume than did female patients. A weight change of 5 kg to10 kg was associated with approximately double the change in computed tomography parameters/Δ5 kg than any weight change after 10 kg. Regardless of weight change, all measured hernia parameters increased over time, with mean hernia volume of +40.6 ± 94.9 cm³/mo and area of +7.8 ± 13.3 cm²/mo (Spearman's correlation coefficient -0.03 to 0.07, P value 0.37-0.96).

CONCLUSION

Weight change is linearly correlated with intra-abdominal and subcutaneous fat gain or loss. Males show greater abdominal-related response to weight gain or loss. Hernia dimensions increase over time regardless of weight change.

Predicting Postoperative Complications after Acute Care Surgery: How Accurate is the ACS NSQIP Surgical Risk Calculator?

The ACS NSQIP Surgical Risk Calculator (SRC) is an evidence-based clinical tool commonly used for evaluating postoperative risk. The goal of this study was to validate SRC-predicted complications by comparing them with observed outcomes in the acute care surgical setting. In this study, pre- and postoperative data from 1693 acute care surgeries (hernia repair, enterolysis, intestinal incision/excision and enterectomy, gastrectomy, debridement, colectomy, appendectomy, cholecystectomy, gastrorrhaphy, and incision and drainage of soft tissue, breast abscesses, and removal of foreign bodies) performed at a Level I trauma center over a five-year time period were abstracted. Predictions for any and serious complications were based on SRC were compared with observed outcomes using various measures of diagnostic. When evaluated as one group, the SRC had good discriminative power for predicting any and serious complications after acute care surgeries (Area Under the Curve (AUC) 0.79, 0.81). In addition, the SRC met Brier score requirements for an informative model overall. However, the predictive accuracy of the SRC varied for various procedures within the acute care patient population. For serious complications, the diagnostic measures ranged from an AUC of 0.61 and negative likelihood ratio of 0.716 for incision & drainage soft tissue to AUC of 0.91 and negative likelihood ratio of 0.064 for gastrorrhaphy. Length of stay was significantly underestimated by the SRC overall (8.56 days, P < 0.01) and for individual procedures. The SRC performs well at predicting complications after acute care surgeries overall; however, there is great variability in performance between procedure types. Further refinements in risk stratification may improve SRC predictions.

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

Panniculectomy procedures have been reported to significantly improve quality of life, increase mobility, and improve hygiene in patients with a significant pannus formation. The primary aims of this study were to determine which preoperative risk factors may be used to differentiate postoperative complication rate among patient cohorts and to validate utilization of the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) risk calculator in patients undergoing panniculectomies.

METHODS

This retrospective study included all patients who underwent a panniculectomy procedure at our institution from 2005 to 2016. Baseline characteristics, preoperative risk factors, medical comorbidities, and postoperative complications were collected via retrospective chart review.

RESULTS

Two hundred sixty-four patients who underwent a panniculectomy were identified. The odds ratios of any postoperative complication were 8.26, 7.76, and 16.6 for patients with classes 1, 2, and 3 obesity, respectively (P < 0.05). Statistical modeling was utilized to evaluate the predictive performance of the ACS-NSQIP Surgical Risk Calculator. We calculated the C-statistic for the ACS-NSQIP model to be only 0.61, indicating that although the model is associated with the risk of complication, it does not have a strong predictive value for this particular procedure.

DISCUSSION

This study is one of the first to characterize postoperative complication rate based on extremum of body mass index for panniculectomy patients. Our results show that the utilization of the ACS-NSQIP Risk Calculator in this particular patient population underestimates the complication risk as a whole, which may necessitate the future development of a separate risk assessment model for this procedure.

Surgeons overestimate postoperative complications and death when compared with the National Surgical Quality Improvement Project risk calculator

BACKGROUND

The assessment of postoperative morbidity and mortality is difficult particularly for complex patients. We hypothesize that surgeons overestimate the risk for complications and death after surgery in complex surgical patients.

MATERIALS AND METHODS

General surgery residents and attending surgeons estimated the likelihood of any morbidity, mortality, surgical site infection, pneumonia, and cardiac complications for seven complex scenarios. Responses were compared with the American College of Surgeons National Surgical Quality Improvement Project Surgical Risk Calculator.

RESULTS

From 101 residents and 48 attending surgeons, overall response rate was 61.7%. For all seven clinical scenarios, there was no difference between resident and attending predictions of morbidity or mortality, with significant variation in estimates among participants. Mean percentages of the estimates were 25.8%-30% over the National Surgical Quality Improvement Project estimates for morbidity and mortality.

CONCLUSIONS

General surgery residents and attending surgeons overestimated risks in complex surgical patients. These results demonstrate broad variance in and near universal overestimation of predicted surgical risk when compared with national, risk-adjusted models.

Predicting complications of major head and neck oncological surgery: an evaluation of the ACS NSQIP surgical risk calculator

Background

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) universal surgical risk calculator is an online tool intended to improve the informed consent process and surgical decision-making. The risk calculator uses a database of information from 585 hospitals to predict a patient’s risk of developing specific postoperative outcomes.

Methods

Patient records at a major Canadian tertiary care referral center between July 2015 and March 2017 were reviewed for surgical cases including one of six major head and neck oncologic surgeries: total thyroidectomy, total laryngectomy, hemiglossectomy, partial glossectomy, laryngopharyngectomy, and composite resection. Preoperative information for 107 patients was entered into the risk calculator and compared to observed postoperative outcomes. Statistical analysis of the risk calculator was completed for the entire study population, for stratification by procedure, and by utilization of microvascular reconstruction. Accuracy was assessed using the ratio of predicted to observed outcomes, Receiver Operating Characteristics (ROC), Brier score, and the Wilcoxon signed–ranked test.

Results

The risk calculator accurately predicted the incidences for 11 of 12 outcomes for patients that did not undergo free flap reconstruction (NFF group), but was less accurate for patients that underwent free flap reconstruction (FF group). Length of stay (LOS) analysis showed similar results, with predicted and observed LOS statistically different in the overall population and FF group analyses (p = 0.001 for both), but not for the NFF group analysis (p = 0.764). All outcomes in the NFF group, when analyzed for calibration, met the threshold value (Brier scores < 0.09). Risk predictions for 8 of 12, and 10 of 12 outcomes were adequately calibrated in the FF group and the overall study population, respectively. Analyses by procedure were excellent, with the risk calculator showing adequate calibration for 7 of 8 procedural categories and adequate discrimination for all calculable categories (6 of 6).

Conclusion

The NSQIP-RC demonstrated efficacy for predicting postoperative complications in head and neck oncology surgeries that do not require microvascular reconstruction. The predictive value of the metric can be improved by inclusion of several factors important for risk stratification in head and neck oncology.

Comparison of Surgeon Specialty in Open Ventral Hernia Repair

BACKGROUND

Ventral hernia repair is a common procedure and is undertaken by surgeons with varying training backgrounds. Outcomes after hernia repair depend on numerous factors, some being patient or surgeon specific. It remains unclear what the ideal roles are for general and plastic surgeons in open ventral hernia repair. We hypothesized that open ventral hernia repair by plastic surgeons is safe and comparable with general surgeons.

METHODS

We performed a retrospective observational study using data from the National Surgical Quality Improvement Program database from 2007 to 2013. Patients with a primary diagnosis of ventral hernia undergoing open repair were identified. Multivariate regression modeling was performed, adjusting for surgeon specialty, patient characteristics, common concurrent procedures, and the total number of concurrent procedures. Outcomes studied were major and minor 30-day complications, operation time, readmission, unplanned reoperation, and length of hospital stay.

RESULTS

We identified 53,746 patients who underwent open repair, 53,282 (99.1%) by general surgeons (GS) and 464 (0.9%) by plastic surgeons (PS). There were significantly different rates of concurrent panniculectomy (12.1% PS vs 2.4% GS) and component separation (24.8% PS vs 5.3% GS), representing increased PS case complexity. 52.3% of GS and 92.9% of PS performed panniculectomy without an alternate specialty surgeon. 81.3% of GS and 97.4% of PS performed component separation without an alternate specialty surgeon. The PS patients had a significantly longer uncorrected length of stay and operation time than GS patients (all P < 0.001). Similarly, PS was positively associated with uncorrected major and minor complications (P < 0.001). However, these relationships did not persist on multivariate analysis after adjusting for demographic characteristics, medical comorbidities, concurrent procedures, and total procedure load. Furthermore, PS was associated with lower odds of major complications (operating room, 0.49; P = 0.05) compared with GS.

CONCLUSIONS

Outcomes of hernia repair by plastic surgeons are comparable with general surgeons, despite plastic surgeons being involved in many complex cases. Interestingly, we identified that general surgeons are performing adjunctive procedures to ventral hernia previously handled by plastic surgeons. Although further study is warranted, we conclude that for open ventral hernia repair, plastic surgeons provide a comparable alternative to general surgeons.

National Surgical Quality Improvement Program surgical risk calculator poorly predicts complications in patients undergoing radical cystectomy with urinary diversion

PURPOSE

To evaluate the accuracy of the American College of Surgeons National Surgical Quality Improvement Programs (ACS-NSQIP) surgical risk calculator in patients undergoing radical cystectomy (RC) with urinary diversion.

MATERIALS AND METHODS

Preoperative characteristics of patients who underwent RC with ileal conduit or orthotropic neobladder (ONB) between 2007 and 2016 were entered into the proprietary online ACS-NSQIP calculator to generate 30-day predicted risk profiles. Predicted and observed outcomes were compared by measuring Brier score (BS) and area under the receiver operating characteristic curve (AUC).

RESULTS

Of 954 patients undergoing RC, 609 (64%) received ileal conduit and 345 (36%) received ONB. The calculator underestimated most risks by 10%-81%. The BSs exceeded the acceptable threshold of 0.01 and AUC were less than 0.8 for all outcomes in the overall cohort. The mean (standard deviation) predicted vs. observed length of stay was 9 (1.5) vs. 10.6 (7.4) days (Pearson's r = 0.09). Among patients who received ONB, adequate BS (<0.01) was observed for pneumonia, cardiac complications, and death. The receiver operating characteristic curve analysis revealed moderate accuracy of calculator for cardiac complications (AUC = 0.69) and discharge to rehab center (AUC = 0.75) among patients who underwent RC with ONB.

CONCLUSIONS

The universal ACS-NSQIP calculator poorly predicts most postoperative complications among patients undergoing RC with urinary diversion. A procedure-specific risk calculator is required to better counsel patients in the preoperative setting and generate realistic quality measures.

American College of Surgeons NSQIP Risk Calculator Accuracy for Emergent and Elective Colorectal Operations

BACKGROUND

The American College of Surgeons NSQIP has developed a risk calculator (RC) to assist patients and surgeons with difficult decisions. The aim of this analysis was to determine the accuracy of the RC in patients undergoing elective and emergent colorectal operations.

STUDY DESIGN

From January 2013 through December 2015, seventy-five patients undergoing emergent colorectal operations were paired by date with 75 patients having elective colorectal operations. Patient data were entered into the RC. Actual postoperative outcomes, derived from NSQIP data, were compared with those predicted by the RC.

RESULTS

Emergent and elective patients differed (p < 0.05) with respect to age, functional status, American Society of Anesthesiologists class, steroid use, wound class, COPD, and chronic renal insufficiency. The RC accurately predicted outcomes in elective patients. Outcomes were significantly worse (p < 0.05) after the emergent operations. In emergent cases, the RC underestimated serious complications and length of stay and overestimated discharge to a skilled nursing facility (all p < 0.05).

CONCLUSIONS

The American College of Surgeons NSQIP RC accurately predicts outcomes for elective colorectal operations. Predicted and actual outcomes are significantly better in patients undergoing elective colon operations compared with those undergoing emergent procedures. The RC should be used with caution in emergent cases, as it has the potential to underestimate serious complications and length of stay, and overestimate discharge to skilled nursing facility. Refinement of the tool to include procedure complexity and diagnosis terms might improve its accuracy in emergent cases.

Development of a Clinically Actionable Incisional Hernia Risk Model after Colectomy Using the Healthcare Cost and Utilization Project

BACKGROUND

Incisional hernia remains a persistent and burdensome complication after colectomy. Through individualized risk-assessment and prediction models, we aimed to improve preoperative risk counseling for patients undergoing colectomy; identify modifiable preoperative risk factors; and encourage the use of evidence-based risk-prediction instruments in the clinical setting.

STUDY DESIGN

A retrospective review of the Healthcare Cost and Utilization Project data was conducted for all patients undergoing either open or laparoscopic colectomy as identified through the state inpatient databases of California, Florida, and New York in 2009. Incidence of incisional hernia repair was collected from both the state inpatient databases and the state ambulatory surgery and services databases in the 3 states between index surgery and 2011. Hernia risk was calculated with multivariable hierarchical logistic regression modeling and validated using bootstrapping techniques. Exclusion criteria included concurrent hernia, metastasis, mortality, and age younger than 18 years. Inflation-adjusted expenditure estimates were calculated.

RESULTS

Overall, 30,741 patients underwent colectomy, one-third of these procedures performed laparoscopically. Incisional hernia repair was performed in 2,563 patients (8.3%) (27-month follow-up). Fourteen significant risk factors were identified, including open surgery (odds ratio = 1.49; p < 0.0001), obesity (odds ratio = 1.49; p < 0.0001), and alcohol abuse (odds ratio = 1.39; p = 0.010). Extreme-risk patients experienced the highest incidence of incisional hernia (19.8%) vs low-risk patients (3.9%) (C-statistic = 0.67).

CONCLUSIONS

We present a clinically actionable model of incisional hernia using all-payer claims after colectomy. The data presented can structure preoperative risk counseling, identify modifiable patient-specific risk factors, and advance the field of risk prediction using claims data.

Foramen of Winslow hernia: a minimally invasive approach

Hernias through the foramen of Winslow comprise 8 % of all internal hernias and the majority contain incarcerated bowel. Clinical signs are often non-specific and delay in diagnosis associated with a mortality rate that approaches 50 %. Management is urgent surgical reduction with bowel decompression and resection of devitalized bowel. A foramen of Winslow hernia (FWH) has traditionally been managed via an exploratory laparotomy incision and the vast majority of cases describe an open approach. We describe a minimally invasive approach to the management of an incarcerated FWH requiring decompression and bowel resection.