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

POSSUM and P-POSSUM as predictors of postoperative morbidity and mortality in patients undergoing hepato-biliary-pancreatic surgery: a meta-analysis

BACKGROUND

Physiologic and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) models are used extensively to predict postoperative morbidity and mortality in general surgery. The aim was to undertake the first meta-analysis of the predictive value of these models in patients undergoing hepato-biliary-pancreatic surgery.

METHODS

Eligible articles were identified by searches of electronic databases from 1991 to 2012. All data were specific to hepato-biliary-pancreatic surgery. Predictive value of morbidity and mortality were assessed by calculating weighted observed to expected (O/E) ratios. Subanalysis was also performed.

RESULTS

Sixteen studies were included in final review. The morbidity analysis included nine studies on POSSUM with a weighted O/E ratio of 0.78 [95 % confidence interval (CI) 0.68-0.88]. The mortality analysis included seven studies on POSSUM and nine studies on P-POSSUM (Portsmouth predictor equation for mortality). Weighted O/E ratios for mortality were 0.35 (95 % CI 0.17-0.54) for POSSUM and 0.95 (95 % CI 0.65-1.25) for P-POSSUM. POSSUM had more accuracy to predict morbidity after pancreatic surgery (O/E ratio 0.82; 95 % CI 0.72-0.92) than after hepatobiliary surgery (O/E ratio 0.66; 95 % CI 0.57-0.74), in large sample size studies (O/E ratio 0.90; 95 % CI 0.85-0.96) than in small sample size studies (O/E ratio 0.69; 95 % CI 0.59-0.79).

CONCLUSIONS

POSSUM overpredicted postoperative morbidity after hepato-biliary-pancreatic surgery. Predictive value of POSSUM to morbidity was affected by the type of surgery and the sample size of studies. Compared with POSSUM, P-POSSUM was more accurate for predicting postoperative mortality. Modifications to POSSUM and P-POSSUM are needed for audit in hepato-biliary-pancreatic surgery.

A systematic review of the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity and its Portsmouth modification as predictors of post-operative morbidity and mortality in patients undergoing pancreatic surgery

BACKGROUND

The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) model and its Portsmouth modification (P-POSSUM) are used extensively to predict postoperative mortality and morbidity in general surgery. The aim of this study was to undertake the first systematic review of the predictive value of these models in patients undergoing pancreatic surgery.

METHODS

Eligible articles were identified by searches of electronic databases for those published from 1991 to 2012. Two independent reviewers assessed each study against inclusion and exclusion criteria. All data were specific to pancreatic surgery. Predictive value of morbidity and mortality were assessed by calculating observed/expected ratios.

RESULTS

Nine studies were included in the final review. The morbidity analysis included 8 studies (1,734 patients) of POSSUM with a weighted observed/expected ratio of .85. The mortality analysis included 5 studies (936 patients) of POSSUM and 4 studies (716 patients) of P-POSSUM. Weighted observed/expected ratios for mortality were .35 for POSSUM and 1.39 for P-POSSUM.

CONCLUSIONS

POSSUM overpredicted postoperative morbidity in patients undergoing pancreatic surgery. Both POSSUM and P-POSSUM failed to offer significant predictive value for mortality in pancreatic surgery, and more data collection in large populations undergoing pancreatic surgery are needed.

Minilaparotomy to rectal cancer has higher overall survival rate and earlier short-term recovery

AIM: To report our experience using mini-laparotomy for the resection of rectal cancer using the total mesorectal excision (TME) technique.

METHODS: Consecutive patients with rectal cancer who underwent anal-colorectal surgery at the authors’ hospital between March 2001 and June 2009 were included. In total, 1415 patients were included in the study. The cases were divided into two surgical procedure groups (traditional open laparotomy or mini-laparotomy). The mini-laparotomy group was defined as having an incision length ≤ 12 cm. Every patient underwent the TME technique with a standard operation performed by the same clinical team. The multimodal preoperative evaluation system and postoperative fast track were used. To assess the short-term outcomes, data on the postoperative complications and recovery functions of these cases were collected and analysed. The study included a plan for patient follow-up, to obtain the long-term outcomes related to 5-year survival and local recurrence.

RESULTS: The mini-laparotomy group had 410 patients, and 1015 cases underwent traditional laparotomy. There were no differences in baseline characteristics between the two surgical procedure groups. The overall 5-year survival rate was not different between the mini-laparotomy and traditional laparotomy groups (80.6% vs 79.4%, P = 0.333), nor was the 5-year local recurrence (1.4% vs 1.5%, P = 0.544). However, 1-year mortality was decreased in the mini-laparotomy group compared with the traditional laparotomy group (0% vs 4.2%, P < 0.0001). Overall 1-year survival rates were 100% for Stage I, 98.4% for Stage II, 97.1% for Stage III, and 86.6% for Stage IV. Local recurrence did not differ between the surgical groups at 1 or 5 years. Local recurrence at 1 year was 0.5% (2 cases) for mini-laparotomy and 0.5% (5 cases) for traditional laparotomy (P = 0.670). Local recurrence at 5 years was 1.5% (6 cases) for mini-laparotomy and 1.4% (14 cases) for traditional laparotomy (P = 0.544). Days to first ambulation (3.2 ± 0.8 d vs 3.9 ± 2.3 d, P = 0.000) and passing of gas (3.5 ± 1.1 d vs 4.3 ± 1.8 d, P = 0.000), length of hospital stay (6.4 ± 1.5 d vs 9.7 ± 2.2 d, P = 0.000), anastomotic leakage (0.5% vs 4.8%, P = 0.000), and intestinal obstruction (2.2% vs 7.3%, P = 0.000) were decreased in the mini-laparotomy group compared with the traditional laparotomy group. The results for other postoperative recovery function indicators, such as days to oral feeding and defecation, were similar, as were the results for immediate postoperative complications, including the physiologic and operative severity score for the enumeration of mortality and morbidity score.

CONCLUSION: Mini-laparotomy, as conducted in a single-centre series with experienced TME surgeons, is a safe and effective new approach for minimally invasive rectal cancer surgery. Further evaluation is required to evaluate the use of this approach in a larger patient sample and by other surgical teams.

Anesthesia and perioperative management of colorectal surgical patients - A clinical review (Part 1)

Colorectal surgery is commonly performed for colorectal cancer and other pathology such as diverticular and inflammatory bowel disease. Despite significant advances, such as laparoscopic techniques and multidisciplinary recovery programs, morbidity and mortality remain high and vary among surgical centers. The use of scoring systems and assessment of functional capacity may help in identifying high-risk patients and predicting complications. An understanding of perioperative factors affecting colon blood flow and oxygenation, suppression of stress response, optimal fluid therapy, and multimodal pain management are essential. These fundamental principles are more important than any specific choice of anesthetic agents. Anesthesiologists can significantly contribute to enhance recovery and improve the quality of perioperative care.

Colorectal stenting as a bridge to surgery reduces morbidity and mortality in left-sided malignant obstruction: a predictive risk score-based comparative study

BACKGROUND

The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity model, and its Portsmouth and colorectal modifications are used to predict postoperative mortality and morbidity after colorectal surgery.

AIMS

To compare stent placement as a bridge to surgery vs. emergency surgical resection in patients with acute left-sided colorectal cancer obstruction using P-POSSUM and CR-POSSUM.

METHODS

From January 2008 to December 2009, the physiological and operative scores, morbidity and mortality predicted by the P-POSSUM and CR-POSSUM scores were collected in all consecutive patients with LCCO who underwent surgical resection directly (Group A) or after stent placement (Group B).

RESULTS

Eighty-six patients were enrolled (Group A-41 and Group B-45). The observed 30-day mortality rate was 9.8% (4/41) in Group A and 2.4% (1/45) in Group B. The 30-day morbidity rate was 61% (25/41) in Group A and 29% (13/45) in Group B. The mean values of P-POSSUM morbidity (A=70.5% vs. B=34.3%; p=0.001), P-POSSUM mortality (A=13.6% vs. B=2.4%; p=0.001) and CR-POSSUM mortality (A=15.1% vs. B=4.9%; p=0.001) were significantly lower in the Group B patients than in the Group A patients.

CONCLUSIONS

Bridge to surgery strategy reduces the surgical risks in LCCO, and P-POSSUM and CR-POSSUM scores represent a good tool for comparing the two strategies.

Determinants of short- and long-term outcome in patients undergoing simultaneous resection of colorectal cancer and synchronous colorectal liver metastases

PURPOSE

The optimal surgical strategy for patients presenting with colorectal liver metastases has yet to be determined. Short- and long-term outcomes must be considered if simultaneous resection of primary and liver metastases is to gain acceptance. We examine the prognostic value of patient and tumour characteristics in predicting short- and long-term outcomes following simultaneous resection for synchronous disease.

METHODS

Forty-six patients undergoing simultaneous resection between April 2002 and June 2010 in a single institution were included. Patient characteristics included preoperative ASA grade and POSSUM. Tumour characteristics included TNM stage, Petersen Index and the Clinical Risk Score.

RESULTS

There were no postoperative deaths. The most common complications were atrial fibrillation (seven patients) and pneumonia (seven patients). Mean hospital stay with an uncomplicated postoperative recovery was 11 days versus 17 days with complicated recovery. Age (p = 0.015), ASA grade (p = 0.010) and POSSUM score (p = 0.032) were associated with postoperative complications. No pathological characteristics of the primary or secondary tumours related to surgical morbidity. Median follow-up was 37 months (5-87) during which 24 patients died, 23 from cancer. Twenty-seven had disease recurrence. N stage of the primary (p = 0.035), high-risk Petersen Index of the primary (p = 0.010) and Clinical Risk Score ≥ 3 (p = 0.005) were associated with poorer recurrence-free and cancer-specific survival.

CONCLUSIONS

Post operative morbidity was determined by patient factors rather than operative or tumour characteristics. In addition to the Clinical Risk Score, pathological characteristics of the primary are important determinants of long-term outcome following simultaneous resection for synchronous disease.

Diagnostic accuracy of C-reactive protein and white blood cell counts in the early detection of inflammatory complications after open resection of colorectal cancer: a retrospective study of 1,187 patients

PURPOSE

Although widely used, there is a lack of evidence concerning the diagnostic accuracy of C-reactive protein (CRP) and white blood cell counts (WBCs) in the postoperative period. The aim of this study was to evaluate the diagnostic accuracy of CRP and WBCs in predicting postoperative inflammatory complications after open resection of colorectal cancer.

METHODS

In this retrospective study, clinical data and the CRP and WBCs, routinely measured until postoperative day 5 (POD 5), were available for 1,187 patients who underwent colorectal cancer surgery between 1997 and 2009. Using the receiver-operating characteristic (ROC) methodology, the diagnostic accuracy was evaluated according to the area under the curve (AUC).

RESULTS

Three hundred forty-seven patients (29.2%; 95% CI, 26.7-31.9%) developed various inflammatory complications. Anastomotic leakage occurred in 8.0% (95% CI, 6.1-9.1%) of patients. The CRP level on POD 4 (AUC 0.76; 95% CI, 0.71-0.81) had the highest diagnostic accuracy for the early detection of inflammatory complications. With a cutoff of 123 mg/l, the sensitivity was 0.66 (95% CI, 0.56-0.74), and the specificity was 0.77 (95% CI, 0.71-0.82). The diagnostic accuracy of the WBC was significantly lower compared to CRP.

CONCLUSION

Measurement of CRP on POD 4 is recommended to screen for inflammatory complications. CRP values above 123 mg/l on POD 4 should raise suspicion of inflammatory complications, although the discriminatory performance was insufficient to provide a single threshold that could be used to correctly predict inflammatory complications in clinical practice. WBC measurement contributes little to the early detection of inflammatory complications.

The revised ACPGBI model is a simple and accurate predictor of operative mortality after potentially curative resection of colorectal cancer

BACKGROUND

The Association of Coloproctology of Great Britain and Ireland (ACPGBI) risk-adjustment model for colorectal cancer surgery has been recently revised. The aim of the present study was to compare the performance of the revised ACPGBI model, the original ACPGBI model, P-POSSUM, and CR-POSSUM, in the prediction of operative mortality after resection of colorectal cancer.

METHODS

A total of 423 patients who underwent potentially curative resection of colorectal cancer at a single institution (1997-2007) were included. Data used in the construction of the ACPGBI model was collected prospectively. The models were compared by examining observed to expected (O:E) ratios, the Hosmer-Lemeshow (H-L) goodness-of-fit test, and area under the receiver operator characteristic curve (AUC) analysis.

RESULTS

The 30-day mortality rate was 4%. The performance of the models was as follows: revised ACPGBI model (O:E ratio = 1.05, AUC = 0.73, H-L = 11.02), original ACPGBI model (O:E ratio = 0.58, AUC = 0.76, H-L = 14.23), P-POSSUM (O:E ratio = 0.87, AUC = 0.79, H-L = 10.63), and CR-POSSUM (O:E ratio = 0.63, AUC = 0.84, H-L = 15.84). In subgroup analysis, the revised ACPGBI model performed well in both elective cases (O:E ratio = 1.06) and emergency cases (O:E ratio = 0.91).

CONCLUSIONS

The revised ACPGBI model is simple to construct and accurately predicts operative mortality after potentially curative resection of colorectal cancer.

The postoperative anaesthetic review

An anaesthetic preoperative assessment for all patients is the standard of care in UK hospitals. The Royal College of Anaesthetists (RCoA) 2009 guidelines state that a postoperative visit, within 24 hours following surgery, is recommended for patients only in certain circumstances. This article critiques these guidelines and explores factors which must be taken into consideration when deciding whether or not anaesthetists should routinely visit their patients after they leave the recovery area. We discuss the physiological rationale for performing a postoperative anaesthetic visit; the identification of post-operative morbidity including provision of adequate post-operative analgesia; patient benefits; limitations of performing postoperative review, and the implications that expanding anaesthetists' responsibilities as perioperative physicians has had upon anaesthetic training and service provision. Finally, this article offers an alternative model for deciding when to perform a post-anaesthetic visit.

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.