Comparison of outcome of POSSUM, p-POSSUM, and cr-POSSUM scoring after elective resection of the sigmoid colon for carcinoma or complicated diverticular disease

Impact of bowel preparation on elective colectomies for diverticulitis: analysis of the NSQIP database

BACKGROUND

Recent data based on large databases show that bowel preparation (BP) is associated with improved outcomes in patients undergoing elective colorectal surgery. However, it remains unclear whether BP in elective colectomies would lead to similar results in patients with diverticulitis. The purpose of this study was to investigate whether bowel preparation affected the surgical site infections (SSI) and anastomotic leakage (AL) in patients with diverticulitis undergoing elective colectomies.

STUDY DESIGN

We identified 16,380 diverticulitis patients who underwent elective colectomies from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) colectomy targeted database (2012-2017). Multivariate logistic regression models were employed to investigate the impact of different bowel preparation strategies on postoperative complications, including SSI and AL.

RESULTS

In the identified population, a total of 2524 patients (15.4%) received no preparation (NP), 4715 (28.8%) mechanical bowel preparation (MBP) alone, 739 (4.5%) antibiotic bowel preparation (ABP) alone, and 8402 (51.3%) MBP + ABP. Compared to NP, patients who received any type of bowel preparations showed a significantly decreased risk of SSI and AL after adjustment for potential confounders (SSI: MBP [OR = 0.82, 95%CI: 0.70-0.96], ABP [0.69, 95%CI: 0.52-0.92]; AL: MBP [OR = 0.66, 95%CI: 0.51-0.86], ABP [0.56, 95%CI: 0.34-0.93]), where the combination type of MBP + ABP had the strongest effect (SSI:OR = 0.58, 95%CI:0.50-0.67; AL:OR = 0.46, 95%CI:0.36-0.59). The significantly decreased risk of 30-day mortality was observed in the bowel preparation of MBP + ABP only (OR = 0.32, 95%CI: 0.13-0.79). After the further stratification by surgery procedures, patients who received MBP + ABP showed consistently lower risk for both SSI and AL when undergoing open and laparoscopic surgeries (Open: SSI [OR = 0.51, 95%CI: 0.37-0.69], AL [OR = 0.47, 95%CI: 0.25-0.91]; Laparoscopic: SSI [OR = 0.58, 95%CI: 0.47-0.72, AL [OR = 0.49, 95%CI: 0.35-0.68]).

CONCLUSIONS

MBP + ABP for diverticulitis patients undergoing elective open or laparoscopic colectomies was associated with decreased risk of SSI, AL, and 30-day mortality. Benefits of MBP + ABP for diverticulitis patients underwent robotic surgeries warrant further investigation.

Australasian ACPGBI risk prediction model for 30-day mortality after colorectal cancer surgery

BACKGROUND

Postoperative mortality after colorectal cancer surgery varies across hospitals and countries. The aim of this study was to test the Association of Coloproctologists of Great Britain and Ireland (ACPGBI) models as predictors of 30-day mortality in an Australian cohort.

METHODS

Data from patients who underwent surgery in six hospitals between 1996 and 2015 (CRC data set) were reviewed to test ACPGBI models, and patients from 79 hospitals in the Bi-National Colorectal Cancer Audit between 2007 and 2016 (BCCA data set) were analysed to validate model performance. Recalibrated models based on ACPGBI risk models were developed, tested and validated on a data set of Australasian patients.

RESULTS

Of 18 752 patients observed during the study, 6727 (CRC data set) and 3814 (BCCA data set) were analysed. The 30-day mortality rate was 1·1 and 3·5 per cent in the CRC and BCCA data sets respectively. Both the original and revised ACPGBI models overestimated 30-day mortality for the CRC data set (observed to expected (O/E) ratio 0·17 and 0·21 respectively). Their ability to correctly predict mortality risk was poor (P < 0·001, Hosmer-Lemeshow test); however, the area under the curve for both models was 0·88 (95 per cent c.i. 0·85 to 0·92) showing good discriminatory power to classify 30-day mortality. The recalibrated original model performed well for calibration and discrimination, whereas the recalibrated revised model performed well for discrimination but not for calibration. Risk prediction was good for both recalibrated models. On external validation using the BCCA data set, the recalibrated models underestimated mortality risk (O/E ratio 3·06 and 2·98 respectively), whereas both original and revised ACPGBI models overestimated the risk (O/E ratio 0·48 and 0·69). All models showed similar good discrimination.

CONCLUSION

The original and revised ACPGBI models overpredicted risk of 30-day mortality. The new Australasian calibrated ACPGBI model needs to be tested further in clinical practice.

Model for End-stage Liver Disease (MELD) in Predicting Postoperative Mortality of Patients Undergoing Colorectal Surgery

The Model for End-stage Liver Disease (MELD) score was previously shown to predict perioperative mortality in patients with cirrhosis undergoing a variety of nontransplant surgical procedures. We sought to determine its usefulness in predicting postoperative mortality in patients undergoing colorectal procedures. National Surgical Quality Improvement Program data were gathered for adult patients undergoing elective and emergent colorectal procedures (Current Procedural Terminology codes 44005 through 45563 excluding appendectomy) during 2005 and 2006 at participating centers. The preoperative MELD score was calculated for all patients and assessed using logistic regression modeling. A total of 10,033 patients met study inclusion criteria. Overall 30-day mortality was 6.6 per cent. In all patients undergoing colorectal surgery, MELD was anindependent predictor of mortality (2.95 [2.27 to 3.84]). Other independent predictors included age, functional status, American Society of Anesthesiologists classification, ascites, esophageal varices, disseminated cancer, chronic steroid use, cardiac disease, renal failure, malnutrition, sepsis, emergency, and ventilator dependence. The MELD score is an independent predictor of mortality in patients undergoing colorectal procedures. These data can be used to assign risk and assist in clinical decision-making.

A novel simplified scoring system for predicting mortality in emergency colorectal surgery: prediction model development

BACKGROUND

Despite advances in surgical approaches, emergency colorectal surgery has high mortality and morbidity.

OBJECTIVE

We aimed to create a simple and distinctive scoring system, for predicting mortality among patients undergoing emergency colorectal surgery.

DESIGN AND SETTING

Prediction model development study based on retrospective data-gathering.

METHODS

Patients who underwent emergency colorectal surgery between March 2014 and December 2016 at a single tertiary-level referral center were included in our study. Patient demographics, comorbidities, type of surgery, etiology and laboratory and radiological findings were collected retrospectively and analyzed. A new clinical score (named the Numune emergency colorectal resection score) was constructed from the last logistic regression model, in which one point was assigned for the presence of each predictive factor.

RESULTS

138 patients underwent emergency colorectal surgery. These comprised 64 males (46.4%) and 74 females (53.6%), with a mean age of 64 years. Multivariate analysis revealed that blood urea nitrogen level > 65 mg/dl (odds ratio, OR: 8.03; 95% confidence interval, CI: 2.16-15.77), albumin level < 0.7 -mg/-dl (OR: 4.43; 95% CI: 1.96-14.39) and American Society of Anesthesiologists score ≥ 3 (OR: 3.47; 95% CI: 0.81-9.18) were associated with postoperative complications. The Numune score was graded from I to III. The risk of mortality was found to be 63.2% in the group with grade III, which accounted for 35.2% of the subjects. There were 37 postoperative deaths.

CONCLUSIONS

Surgeons need scoring systems, especially to predict postoperative mortality. We propose the Numune emergency colorectal resection score for emergency surgical procedures as a practical, usable and effective system for predicting postoperative morbidity.

The applicability of POSSUM and P-POSSUM scores as predictors of morbidity and mortality in colorectal surgery

OBJECTIVE

to apply the POSSUM and P-POSSUM scores as a tool to predict morbidity and mortality in colorectal surgery.

METHODS

we conducted a prospective cohort study of 551 patients submitted to colorectal surgery in a colorectal surgery tertiary referral hospital in Brazil. We grouped patients into pre-established risk categories for comparison between expected and observed morbidity and mortality rates by the POSSUM and P-POSSUM scores.

RESULTS

in the POSSUM morbidity analysis, the overall expected morbidity was significantly higher than that observed (39.2% vs. 15.6%). The same occurred with patients grouped in categories II (28.9% x 10.5) and III (64.6% x 24.5%). In category I, the expected and observed morbidities were similar (13.7% x 9.1%). Regarding the evaluation of mortality, it was statistically higher than that observed in category III patients and in the total number of patients (11.3% vs. 5.6%). In categories I and II, we observed the same pattern of category III, but without statistical significance. When evaluating mortality by the P-POSSUM score, the overall expected and observed mortality was similar (5.8% x 5.6%). Of the 31 patients who died, 20.2% underwent emergency procedures and sepsis was the main cause of death.

CONCLUSION

the P-POSSUM score was an accurate tool to predict mortality and could be safely used in this population profile, unlike the POSSUM score.

Colorectal surgical mortality and morbidity in elderly patients: comparison of POSSUM, P-POSSUM, CR-POSSUM, and CR-BHOM

PURPOSE

This study aims to compare the predictive value of POSSUM, P-POSSUM, CR-POSSUM and CR-BHOM in colorectal surgical mortality and morbidity in patients over 80 years old.

METHODS

This is a retrospective observational longitudinal study. A total of 991 patients who underwent major colorectal surgery between 2008 and 2012 in a secondary hospital in Portugal were screened, and 204 who were over 80 years old were included. Subgroup analysis was performed for malignant/benign disease and emergent/elective surgery. The main outcome measure was 30-day postoperative mortality and morbidity with Clavien-Dindo classification ≥ 2.

RESULTS

Of the 204 patients included in this study, 155 had malignant disease, and 65 underwent emergent procedures. Overall average age was 84.3 ± 3.9 years (range 80-100). Overall surgical mortality and morbidity were 18.6% (n = 38) and 52.4% (n = 87), respectively. Expected mortality followed the order P-POSSUM<CR-POSSUM<CR-BHOM (p < 0.001), and expected morbidity followed the order POSSUM<CR-BHOM (p < 0.001) in all groups. All scores were higher in the emergent surgery group compared with elective surgery (p < 0.05). All scores had sensitivity below 60%. Physiology scores were higher among patients with surgical mortality (p < 0.05), with no differences in operative scores.

CONCLUSIONS

In our population, CR-POSSUM was the best predictor of surgical mortality. POSSUM and P-POSSUM underestimated surgical mortality and morbidity, and CR-BHOM overestimated surgical mortality, being however the best predictor of morbidity. Nevertheless, none of the scores showed sufficient discriminatory power to have clinical application value. Moreover, our results suggest that, in elderly patients, it is the patient's health status and not the type of surgery that is mainly responsible for the surgical outcome.

Predictive value of POSSUM and ACPGBI scoring in mortality and morbidity of colorectal resection: a case-control study

BACKGROUND

Preoperative risk prediction to assess mortality and morbidity may be helpful to surgical decision making. The aim of this study was to compare mortality and morbidity of colorectal resections performed in a tertiary referral center with mortality and morbidity as predicted with physiological and operative score for enumeration of mortality and morbidity (POSSUM), Portsmouth POSSUM (P-POSSUM), and colorectal POSSUM (CR-POSSUM). The second aim of this study was to analyze the accuracy of different POSSUM scores in surgery performed for malignancy, inflammatory bowel diseases, and diverticulitis. POSSUM scoring was also evaluated in colorectal resection in acute vs. elective setting. In procedures performed for malignancy, the Association of Coloproctology of Great Britain and Ireland (ACPGBI) score was assessed in the same way for comparison.

METHODS

POSSUM, P-POSSUM, and CR-POSSUM predictor equations for mortality were applied in a retrospective case-control study to 734 patients who had undergone colorectal resection. The total group was assessed first. Second, the predictive value of outcome after surgery was assessed for malignancy (n = 386), inflammatory bowel diseases (n = 113), diverticulitis (n = 91), and other indications, e.g., trauma, endometriosis, volvulus, or ischemia (n = 144). Third, all subgroups were assessed in relation to the setting in which surgery was performed: acute or elective. In patients with malignancy, the ACPGBI score was calculated as well. In all groups, receiver operating characteristic (ROC) curves were constructed.

RESULTS

POSSUM, P-POSSUM, and CR-POSSUM have a significant predictive value for outcome after colorectal surgery. Within the total population as well as in all four subgroups, there is no difference in the area under the curve between the POSSUM, P-POSSUM, and CR-POSSUM scores. In the subgroup analysis, smallest areas under the ROC curve are seen in operations performed for malignancy, which is significantly worse than for diverticulitis and in operations performed for other indications. For elective procedures, P-POSSUM and CR-POSSUM predict outcome significantly worse in patients operated for carcinoma than in patients with diverticulitis. In acute surgical interventions, CR-POSSUM predicts mortality better in diverticulitis than in patients operated for other indications. The ACPGBI score has a larger area under the curve than any of the POSSUM scores. Morbidity as predicted by POSSUM is most accurate in procedures for diverticulitis and worst when the indication is malignancy.

CONCLUSION

The POSSUM scores predict outcome significantly better than can be expected by chance alone. Regarding the indication for surgery, each POSSUM score predicts outcome in patients operated for diverticulitis or other indications more accurately than for malignancy. The ACPGBI score is found to be superior to the various POSSUM scores in patients who have (elective) resection of colorectal malignancy.

Risk-adjusted scoring systems in colorectal surgery

Consequent to recent advances in surgical techniques and management, survival rate has increased substantially over the last 25 years, particularly in colorectal cancer patients. However, post-operative morbidity and mortality from colorectal cancer vary widely across the country. Therefore, standardised outcome measures are emphasised not only for professional accountability, but also for comparison between treatment units and regions. In a heterogeneous population, the use of crude mortality as an outcome measure for patients undergoing surgery is simply misleading. Meaningful comparisons, however, require accurate risk stratification of patients being analysed before conclusions can be reached regarding the outcomes recorded. Sub-specialised colorectal surgical units usually dedicated to more complex and high-risk operations. The need for accurate risk prediction is necessary in these units as both mortality and morbidity often are tools to justify the practice of high-risk surgery. The Acute Physiology And Chronic Health Evaluation (APACHE) is a system for classifying patients in the intensive care unit. However, APACHE score was considered too complex for general surgical use. The American Society of Anaesthesiologists (ASA) grade has been considered useful as an adjunct to informed consent and for monitoring surgical performance through time. ASA grade is simple but too subjective. The Physiological & Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and its variant Portsmouth POSSUM (P-POSSUM) were devised to predict outcomes in surgical patients in general, taking into account of the variables in the case-mix. POSSUM has two parts, which include assessment of physiological parameters and operative scores. There are 12 physiological parameters and 6 operative measures. The physiological parameters are taken at the time of surgery. Each physiological parameter or operative variable is sub-divided into three or four levels with an exponentially increasing score. However, POSSUM and P-POSSUM over-predict mortality in patients who have had colorectal surgery. Discrepancies in these models have led to the introduction of a specialty-specific POSSUM: the ColoRectal POSSUM (CR-POSSUM). CR-POSSUM only uses six physiological parameters and four operative measures for prediction of mortality. It is much simplified to allow ease of use.

A systematic review of POSSUM and its related models as predictors of post-operative mortality and morbidity in patients undergoing surgery for colorectal cancer

INTRODUCTION

The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) model and its Portsmouth (P-POSSUM) and colorectal (CR-POSSUM) modifications are used extensively to predict and audit post-operative mortality and morbidity. This aim of this systematic review was to assess the predictive value of the POSSUM models in colorectal cancer surgery.

METHODS

Major electronic databases, including Medline, Embase, Cochrane Library and Pubmed were searched for original studies published between 1991 and 2010. Two independent reviewers assessed each study against inclusion and exclusion criteria. All data was specific to colorectal cancer surgery. Predictive value was assessed by calculating observed to expected (O/E) ratios.

RESULTS

Nineteen studies were included in final review. The mortality analysis included ten studies (4,799 patients) on POSSUM, 17 studies (6,576 patients) on P-POSSUM and 14 studies (5,230 patients) on CR-POSSUM. Weighted O/E ratios for mortality were 0.31 (CI 0.31-0.32) for POSSUM, 0.90 (CI 0.88-0.92) for P-POSSUM and 0.64 (CI 0.63-0.65) for CR-POSSUM. The morbidity analysis included four studies (768 patients) on POSSUM with a weighted O/E ratio of 0.96 (CI 0.94-0.98).

CONCLUSIONS

P-POSSUM was the most accurate model for predicting post-operative mortality after colorectal cancer surgery. The original POSSUM model was accurate in predicting post-operative complications.

Predicting post-operative mortality in patients undergoing colorectal surgery using P-POSSUM and CR-POSSUM scores: a prospective study

INTRODUCTION

POSSUM and its variants Portsmouth POSSUM (P-POSSUM) and Colorectal POSSUM (CR-POSSUM) equations were derived from a heterogeneous general surgical population, which have been used successfully to provide risk-adjusted operative mortality rates. CR-POSSUM utilises fewer parameters, allowing ease of use. The aim of this study was to predict the mortality outcome in colorectal surgery using these scoring systems compared to the observed mortality and to devise a new scoring system with improved accuracy.

METHODS

The study was conducted prospectively on all consecutive patients requiring elective and emergency colorectal surgery between April 2002 and May 2005. The outcome parameter was defined as 30-day mortality. The observed mortality was compared with predicted mortality by the scoring systems. Hosmer and Lemeshow test was used to assess statistical accuracy of POSSUM.

RESULTS

Eight hundred ninety-nine patients underwent colorectal surgery during the study period. There were 619 elective and 281 emergency patients. Observed 30-day mortality rate was 9%, compared with predicted mortality rate of 13.5% with POSSUM, 5% with P-POSSUM and 9.5% with CR-POSSUM.

CONCLUSION

POSSUM's mortality rate was overestimated, while P-POSSUM's mortality rate was underestimated. CR-POSSUM, the simplest system of all three, most accurately predicted mortality in our unit.

Perioperative outcome of colorectal cancer and validation of CR-POSSUM in a Caribbean country

OBJECTIVE

To evaluate the risk-adjusted perioperative outcome of colorectal cancer surgery, applying the Colorectal Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (CR-POSSUM).

METHODS

A retrospective chart review of patients who underwent colorectal cancer surgery from 2004 to 2007 was done. Data including demographics and physiological data for CR-POSSUM were recorded. Predicted mortality was calculated; validation of CR-POSSUM was done using Hosmer-Lemeshow goodness-of-fit and Receiver Operating Characteristic (ROC) Curve analyses.

RESULTS

232 patients were studied. The overall mean CR-POSSUM score was 18.3+/-3.8 (SD). Predicted mortality was 7.7%, observed mortality was 6.9% and the standardized mortality ratio was 0.9. 34.4% of patients presented with Duke's Stage C or D and had a higher risk of mortality (Odds Ratio (OR) 3.1, 95% Confidence Intervals (CI) 1.1, 9.1). Emergency surgery was associated with a higher risk of mortality (OR 4.7, 95% CI 1.5, 14.1). CR-POSSUM calibrated well (Hosmer-Lemeshow Chi-square value 4.3; df: 8; p=0.82) and fairly discriminated outcome as shown by the area under the ROC Curve 0.69, (Standard Error: 0.07).

CONCLUSIONS

Perioperative outcome of colorectal surgery in Trinidad and Tobago is comparable to the developed countries as evaluated by the CR-POSSUM. Patients presenting for emergency surgery and those with advanced stages of cancer had higher perioperative mortality.